bluuebunny/crossref_metadata_2025 huggingface dataset:
Experiments on Supersonic ORC Nozzles in Linear Cascade Configuration
Authors: Oliveti Marco , Manfredi Marco , Persico Giacomo , Spinelli Andrea , Gaetani Paolo , Dossena Vincenzo
Published: July 2024

In organic Rankine cycles (ORCs), the turbo-expander represents a critical component due to the major impact of its efficiency on working fluid selection, cycle layout and overall plant performance and profitability. Also, its design is complicated by large expansion ratios, by the demand of operational flexibility and by the thermo-physical characteristics of the working fluid and non-ideal gas effects. This typically leads to turbines with low number of stages and transonic/supersonic flow regimes. For these reasons, the ORC turbine design relies on advanced aerodynamic models and high-fidelity tools based on computational fluid dynamics (CFD). The verification of high-fidelity tools requires accurate fluid thermodynamic models and experimental data concerning canonical flows, since experiments on non-ideal flows within ORC turbine cascades are still missing in the literature. To fill this gap, a novel experiment has been designed at Politecnico di Milano on an ORC supersonic linear cascade, aimed at characterizing the flow field within the bladed and semi-bladed portion of the channels, at the trailing edge where shock/fan systems arise, and downstream the cascade, by retrieving the pitch-wise total pressure loss distribution. This paper reports the outcomes of an experimental campaign focused on the expansion of hexamathyldisiloxane (MM) within the cascade. Initial commissioning tests were performed using nitrogen at different pressure levels. Finally, the experimental data gathered during a campaign carried out with MM in non-ideal conditions are presented and compared with CFD simulations, allowing to assess real gas effects on the trailing edge shock pattern and pressure distribution through the cascade.
TECHNICAL COMPARISON AND EVALUATION OF A PUMPED THERMAL ENERGY STORAGE WITH TWO DIFFERENT DESIGNS
Authors: Santos Márcio , André Jorge , Mendes Ricardo , Ribeiro José B.
Published: July 2024

Increased worldwide demand for energy (especially electricity), rising energy costs, and heightened environmental concerns are factors that continually press for the adoption of technologies to exploit renewable energy sources (RES). In order to adopt these systems, large-scale energy storage systems are needed to ensure the security of supply in energy systems due to the increasing share of renewable energy sources in the energy mix. The paper proposes a new form of energy storage technology that utilizes a combination of a heat pump and an organic Rankine cycle, referred to as Carnot Batteries (CB), which can store thermal energy for several hours to a few days and transform it back to electrical energy. Two different configurations of Carnot Batteries were tested using models created in Matlab programming software, with six working fluids used for technical optimization. The second, more complex configuration increased the roundtrip efficiency mainly due to the better performance of the two-stage heat pump.
The potential of CO2-Plume Geothermal (CPG) Systems for CO2 component manufacturers: opportunities and development needs
Authors: Schifflechner Christopher , de Reus Jasper , Spliethoff Hartmut , O. Saar Martin , Schuster Sebastian , Brillert Dieter
Published: July 2024

Subsurface reservoirs play an important role in decarbonizing the energy sector, be it through geothermal energy production or carbon capture and storage (CCS). In recent years, there has been an increasing interest in CO2-Plume Geothermal (CPG) systems, which combine CCS with geothermal, using CO2 instead of water as a subsurface heat and pressure energy carrier. As explained later in the paper, applying CO2 as a subsurface working fluid can be more efficient than water as it has a higher mobility (inverse kinematic viscosity) and as its large thermal expansion coefficient results in a thermosiphon effect that reduces the pumping power required. CO2 can also directly be utilized in a turbine for power generation. Furthermore, since CPG systems are added to full-scale CO2 Capture and Sequestration operations, all of the initially injected CO2 is ultimately stored. CPG therefore constitutes of both CO2 Capture Utilization as well as Storage. This paper assesses the huge technical potential of the CPG technology, identifying a potentially highly relevant market for CO2 equipment manufacturers and discusses the current research demand, based on the current state of the art of CO2 equipment. Both temperature and pressure levels are significantly lower than CO2 turbine designs investigated and proposed so far for other applications, such as waste heat recovery. Together with CPG-specific requirements, due to produced fluid impurities, it becomes evident that significant further development efforts are still necessary regarding future commercial CPG CO2 turbines.
DEVELOPMENT OF A GENERALISED LOW-ORDER MODEL FOR TWIN-SCREW COMPRESSORS
Authors: Kaufmann Florian , Irrgang Ludwig , Schifflechner Christopher , Spliethoff Hartmut
Published: July 2024

Twin-screw compressors (TSC) are commonly used in heat pump processes due to their robustness and flexibility. They exhibit two core properties, i.e. the swept volume and the built-in volume ratio (BVR), which heavily influence their capacity limits and off-design efficiency. Several models of vastly different computational costs have been proposed in literature to calculate the performance of TSCs. For applications that rely on large amounts of simulation runs, the computational cost of the compressor model becomes an essential factor. This work presents a new low-order model, which can accurately predict a TSC’s behaviour. First, a semi-empirical model from literature is slightly adapted and used to generate performance data for a large operational field. Then a polynomial model with a linearisation for high pressure ratios is fitted to this data. The model uses the external pressure ratio and volumetric compressor inlet flow to calculate isentropic efficiency and compressor speed. Both input parameters are normalised with a reference flowrate (calculated from the swept volume) and the BVR, respectively. This results in a generalised model of low numerical cost, which can be used for explorative studies independent of the specific machine size and BVR. A gain in computational speed by a factor of roughly 375 is achieved compared to a semi-empirical reference model. The model displays good predictive accuracy when used to predict the performance of machines with similar BVRs, but different sizes. When there is a difference in size and BVR, the prediction accuracy is still reasonable but significantly declines for small pressure ratios. Nevertheless, the proposed new approach extends the state-of-the-art by introducing a low-order model, which combines the advantages of low computational cost, good accuracy, physically correct predictions over a wide operational range and scalability to different machine capacities and BVRs.
REVERSIBLE HEAT PUMP-ORC PILOT PLANT – EXPERIMENTAL RESULTS AND FLUID CHARGE OPTIMIZATION
Authors: Weitzer Maximilian ,   *, , ,, Kolb Sebastian , Müller Dominik , Karl Jürgen
Published: July 2024

The reversible operation of the heat pump process and the organic Rankine cycle as a Carnot battery has gained attraction of the scientific community in recent years. Despite numerous publications investigating the potential of such systems as a new energy storage technology, experimental results are scarce. The present work presents the outcomes on process level of a first experimental characterization of a reversible heat pump – organic Rankine cycle (HP-ORC) pilot plant designed for a maximum charging capacity of 15 kWel in heat pump mode and discharging capacity of 9 kWel in ORC mode. The experimental campaign comprised 150 stationary operating points. The plant yielded a maximum COP of 9.5 and a maximum ORC net efficiency of 4.4% for the defined boundary conditions of this experimental campaign. While the heat pump favors low temperature lifts for a high COP, high temperature gradients are favorable for ORC operation. Moreover, limitations on component and system level were determined. The challenging aspect of a proper fluid management of such reversible systems was identified as a crucial factor. Finally, the impact of fluid charge on ORC operation was experimentally evaluated and revealed significant optimization potential by means of an adequate fluid management.
PERFORMANCE OF ORGANIC RANKINE CYCLE SYSTEM IN COMBINATION WITH RESIDUAL MUNICIPAL SOLID WASTE GASIFICATION: A SIMULATION ANALYSIS
Authors: Cioccolanti Luca , Biancini Giovanni , Moradi Ramin , Del Zotto Luca , Moglie Matteo
Published: July 2024

Despite recycling is largely adopted in Europe, the amount of disposed municipal solid waste (MSW) from mechanical-biological treatment is increasing. At the same time, more environmentally friendly waste-to-energy (WtE) solutions are needed to promote sustainable management of residual MSW (RMSW) compared to incineration, which is the most common process to valorise MSW. Among the waste-to-energy solutions, gasification is considered a promising option and nowadays attention is paid to the use of residual MSW as feedstock. In addition, organic Rankine cycle (ORC) systems are one of the most suitable technologies to produce electricity from low-grade energy sources such as that obtained from the gasification of residual MSW. Therefore, in this work, a RMSW air gasifier in combination with an ORC unit are investigated using Aspen Plus for combined heat and power (CHP) applications. The simulation analysis is performed considering the potential syngas production from RMSW of a real composting facility in Italy. Three different working fluids are investigated to assess the energy performance of the integrated system for CHP production in district heating networks. The analysis reports an overall conversion efficiency of the integrated system in the range 38.4% - 48.5% and a maximum power production of the ORC unit of 2.14 MWe with the use of toluene. Therefore, the present study shows that the gasification of RMSW and the exploitation of its energy content in an ORC system is a viable option to reduce the environmental burden in compositing facilities by extending the lifetime of the landfills.
ENHANCING KNOWLEDGE OF ENGINEERING STUDENTS AT ALL LEVELS ON ORGANIC RANKINE CYCLE SYSTEMS FOR THEIR APPLICATION IN THE BUILT ENVIRONMENT
Authors: Cioccolanti Luca , Moradi Ramin , Abdullah Ermira , Saadon Syamimi , Yusof Idroas Mohamad , Yew Heng Teoh , Kraitong Kwanchai
Published: July 2024

According to International Energy Agency (IEA), the global energy crisis is accelerating the use of renewable energy in the next five years. Furthermore, the building sector which accounts for about 30% of the final energy consumption, has a significant room for improvement in curbing its share of energy consumption and integrating renewable energy technologies. Hence, the ‘Skybelt’ project, co-funded by the EU under the framework of the Erasmus+ programme and coordinated by eCampus University - Italy, aims at enhancing the skills of engineering students at all levels for application of sustainable renewable energy solutions to be integrated into the built environment in several Asian and European universities. The market analyses conducted in the initial stage of the project have revealed that combined heating and power (CHP) and combined cooling, heating, and power (CCHP) are the most interesting applications of knowledge for future employees on renewable energy. Among the potential CHP and CCHP technologies, Organic Rankine cycle (ORC) systems are interesting for the building energy sector thanks to their capability to be combined with solar and biomass sources. Therefore, Universiti Putra Malaysia (UPM), Universiti Sains Malaysia (USM) and Naresuan University (NU) opted to be equipped with non-regenerative ORC test benches for training of engineering students at different levels. In particular, bachelor students at UPM will work on the development of different control approaches on small-scale ORC units within the modernised module of ‘Control System Analysis’, and students at USM and NU will be trained on the operating performance of these systems to be combined with different renewable energy sources. Hence, the project has given the opportunity to foster knowledge about the ORC systems for engineering students at all levels with the perspective of adopting them in buildings.
On the plant improvement of Solar-driven ORC-based power unit for domestic micro-cogeneration
Authors: Fatigati Fabio , Di Bartolomeo Marco , Coletta Arianna , Vittorini Diego , Di Battista Davide , Di Giovine Giammarco , Cipollone Roberto
Published: July 2024

The integration of flat solar thermal collectors and ORC-based power units ensures the simultaneous production of heat and electric power in domestic applications (CHP). Thus, such micro-cogenerative solutions ensure to reduce the use of fossil fuels and CO2 in a sector that accounted for about 30% of global energy-related CO2 emissions in 2021, considering both residential and commercial buildings. The significant variability of solar power during the day and domestic hot water (DHW) demand pushes the unit to work in off-design and transient conditions frequently. Therefore, to maximize the energy recovery of the unit, the design phase and the components selection assume a crucial role. The critical component is the expander and, generally, volumetric machines are adopted for their operating flexibility and robustness when working with highly variable hot sources. Among the volumetric expanders adopted for this kind of application, scroll machines present higher performance and reliability than other positive displacement technologies. Nevertheless, similarly to the other volumetric expanders, such devices still have room for improvement. Indeed, in many applications, they are obtained by reversing scroll compressors. Hence, to participate in the improvement of these machines, a comprehensive model was developed following an integrated zero and mono-dimensional (0-1D) thermo-fluid-dynamic approach. The model was validated through experimental data measures during a comprehensive testing campaign performed on a fully instrumented solar-driven ORC-based power unit which employs a 1 kW scroll expander as mechanical power at design. Once the scroll expander model was validated, it was theoretically optimized in terms of working fluid flow rate aspiration (volumetric efficiency), indicated performances and mechanical power produced. Subsequently, the benefits of the optimized machine to the recovery unit performances have been estimated.
ACHIEVING 45% MICRO GAS TURBINE EFFICIENCY THROUGH HYBRIDIZATION WITH ORGANIC RANKINE CYCLES
Authors: Escamilla Antonio ,   ,*, 1, 1 1, Sánchez Martínez David , García-Rodríguez Lourdes
Published: July 2024

The demand for affordable, secure, and sustainable energy storage solutions has grown significantly with the increasing focus on decarbonization and the adoption of renewable energy sources (RES). Power-to-Power (P2P) energy storage systems (ESS) have emerged as a promising solution, utilizing excess electricity from RES to produce hydrogen for future power generation. This document presents a study on increasing the round-trip efficiency of P2P ESS by improving the electric efficiency of micro gas turbines (mGT) and integrating waste heat to power (WHP) technology. The research investigates the potential of mGTs as prime movers in P2P ESS, aiming to break the 45% electric efficiency barrier that would make them competitive with other alternatives like internal combustion engines (ICE) and fuel cells (FC). Increasing the nominal electric efficiency of mGTs would lead to significant reductions in hydrogen consumption, system footprint, and overall capital expenditure. Thus, this research focuses on increasing the electrical efficiency of the mGT by proposing a hybridization between the recuperative Brayton cycle and bottoming organic Rankine cycles, reaching higher than 45% electrical efficiencies in a hybrid configuration. An exhaustive comparison of the main ORC systems hybridized with the recuperative Brayton cycles is presented. The results reveal that hybridizing an intercoolingrecuperative Brayton cycle with a simple recuperated ORC has the potential to increase electrical efficiency to 46%. The work also presents a sensitivity analysis to assess how the design parameters influence the performance of the hybrid thermodynamic cycle.
OPERATIONAL OPTIMISATION OF THE MAIN HEAT REJECTION UNIT OF CSP PLANTS BASED ON CARBON DIOXIDE MIXTURES
Authors: Crespi Francesco , Rodríguez-deArriba Pablo , Sánchez David , García-Rodríguez Lourdes
Published: July 2024

This research, developed in the framework of the SCARABEUS project, studies the off-design performance of transcritical power cycles running on CO2-SO2 mixtures in Concentrated Solar Power applications. The objective of this work is to identify optimum operational strategies that maximise net energy production when exposed to variable ambient temperature, with special focus on the operation of the Heat Rejection Unit (Air-Cooled Condenser). The power cycle is simulated in Thermoflex, modified with user-defined scripts to account for the specific off-design performance characteristics of key components. The Air-Cooled Condenser is modelled by means of an in-house Matlab tool, already validated in previous publications, able to accurately simulate the heat transfer process between working fluid and cooling medium (air) and to calculate auxiliary power consumption. Four different strategies are identified, depending on ambient temperature: variable or constant condensation pressure for ambient temperatures lower than the design value, and constant turbine inlet temperature or constant return temperature of the heat transfer fluid for ambient temperature higher than design value. The results show that a combination of variable and constant minimum cycle pressure is the best alternative for low ambient temperatures, enabling net system efficiencies higher than 41%. On the other hand, constant turbine inlet temperature enables higher net performance than constant return temperature of the heat transfer fluid, even if at the expense of a reduction in energy storage capacity for the same inventory of molten salts.
REDUCED ORDER MODELLING OF OPTIMIZED HEAT EXCHANGERS FOR MAXIMUM MASS-SPECIFIC PERFORMANCE OF AIRBORNE ORC WASTE HEAT RECOVERY UNITS
Authors: Beltrame Fabio
Published: July 2024

Waste heat recovery (WHR) from aeroengines via compact organic Rankine cycle (ORC) units may increase the fuel efficiency of air transportation. Heat exchangers are arguably the key components of ORC systems for aeronautical applications and their design must be optimized to guarantee the best trade-off between fluid pressure drop, weight and induced aircraft drag. At present, no heat exchangers design guidelines are available for waste heat recovery systems aboard aircraft. This study, thus, contributes to defining a proper design methodology for ORC systems of such applications. The chosen test case is a supercritical ORC system with cyclopentane as the working fluid, which recovers waste heat from the auxiliary power unit of an aircraft. The exhaust gas temperature and mass flow rate of the power unit are known and kept constant in the analysis, and so are the ambient conditions, which define the cold sink of the ORC turbogenerator. Three design strategies targeting minimum mass and maximum net power output of the ORC unit have been assessed. In the first one, the multi-objective optimization is performed by prescribing a priori the geometry and frontal area of the heat exchangers. Thus, only the cycle parameters are optimized. The second method tackles, instead, the simultaneous optimization of the geometric parameters of the condenser and the cycle parameters. It was found that the integrated design allows for system mass reduction by 10 - 12% for a given ORC power output, highlighting the importance of performing the simultaneous optimization of the thermodynamic process and the heat exchanger geometry. Finally, the third method addresses the same optimal design problem by leveraging a reduced-order model of the condenser to predict the optimal design space of this component. The generated Pareto front obtained with this method is very similar to that found by optimizing simultaneously the complete condenser geometry and the cycle parameters. The mean deviation is about 2%. With just one heat exchanger surrogate model, the Pareto front was generated in one fourth of the computational time. This is due to the lower number of optimization variables and the faster objective function evaluation.
Muzyka a dyplomacja kulturowa, czyli kilka słów o budowaniu marki „hiszpańskości” i muzyce Manuela de Falli (na przykładzie baletu El Amor brujo)
Authors: Piotrowska Anna G.
Published: July 2024

MUSIC AND CULTURAL DIPLOMACY, OR A FEW WORDS ABOUT BUILDING THE BRAND OF SPANISHNESS’ AND THE MUSIC OF MANUEL DE FALLA (ON THE EXAMPLE OF HIS BALLET EL AMOR BRUJO)
Manuel de Falla’s (1876–1946) oeuvre was already discussed in terms of national Spanish music and specific Spanish values during the composer’s lifetime. Following de Falla’s death, some of his compositions, most notably the ballet El Amor brujo (1915), which refers to the culture of Gitanos and the phenomenon of flamenco, began to function as emblematically Spanish works, i.e. representative of contemporary Spanish music. As a result of the cultural diplomacy implemented by the Francoist government, flamenco was endorsed internationally as a hallmark of Spanishness. Works referring to flamenco, such as de Falla’s El Amor brujo, were thus also intensively promoted: numerous film productions referring to flamenco alluding to de Falla’s ballet in the plot and in the musical layer, significantly contributed to the international success of this work.
Son Gokū i Power Rangers w Galicji
Authors: Wróbel Antonina
Published: July 2024

SON GOKŪ AND POWER RANGERS IN GALICIA: THE USE OF JAPANESE POP CULTURE IN THE ARTWORK OF GALICIAN MURALIST YOSEBA MP
My paper discusses the influence of Japanese art on Galician art. Firstly, I provide a historical overview of the Spanish Japanese relations, with particular emphasis on Galicia. Second, the analysis of the works of Galician artist Yoseba MP allows reflection on the changes generated by the application of elements of Japanese pop culture to another cultural area. I put particular emphasis on the figure of the superhero and his transformation to the local context, so as to show how the author engages in a cultural dialogue about the myth of the Galician matriarchy. Although the research part is based on the analysis of the works of only one artist, it allows new approach to Galician culture and the position of women in this society.
Drugie życie silbo gomero – jak edukacja, turystyka i sztuka przyczyniły się do ocalenia gwizdanego języka z Gomery
Authors: Krzyżostaniak Magdalena
Published: July 2024

THE SECOND LIFE OF SILBO GOMERO – THE CONTRIBUTION OF EDUCATION, TOURISM AND ART TO SAVING THE WHISTLED LANGUAGE OF THE ISLAND OF LA GOMERA
Silbo gomero is a whistled language used by inhabitants of La Gomera (Canary Islands) and created before the arrival of Spanish settlers to overcome communication problems resulting from the deep ravines and narrow valleys that radiate through the island. The language, commonly used in the 17th, 18th and 19th centuries, declined in the 1950s–1980s due to economic migration, the growth of tourism and technological developments e.g. the telephone. Since the language was endangered in the late 1990s, revitalization efforts were generated at both community and governmental level. Nowadays, tourism is not a threat to silbo gomero; it’s seen as a great opportunity and as a generator of both employment and income. Unlike other islands in the archipelago, La Gomera focuses on natural resource-based tourism and cultural tourism and silbo gomero seems to be an ideal magnet for tourists looking for something more than the beach and the sun.
Muzea Lizbony – odkrycia i zaskoczenia
Authors: Gaweł Łukasz
Published: July 2024

MUSEUMS OF LISBON – DISCOVERIES AND SURPRISES
Over the past few decades, museums have encountered numerous challenges. These include changing living conditions, evolving social values and needs, social justice issues, decolonisation, the climate crisis, and giving a voice to marginalised groups. As a result, contemporary museums are expected to meet new audience expectations. Some museums have attempted to establish their own identity in response to these challenges. The article presents an analysis of three case studies of museums in Lisbon, demonstrating how different approaches can result in the development of a unique set of values, goals, and objectives that are relevant to the needs of modern societies.
Malamente? Niełatwe relacje lokalności i kultury popularnej w twórczości Rosalíi
Authors: Romanowska Jadwiga
Published: July 2024

MALAMENTE? UNEASY RELATIONS BETWEEN LOCALITY AND POPULAR CULTURE IN ROSALÍA’S WORK
The aim of the text is to ask questions about how contemporary popular culture enters into transcultural interaction with artistic manifestations of local Spanish identities, using the example of selected works by the Catalan artist Rosalía Vila Tobella, known as Rosalía. The artist mediates between several cultural spaces: Spanish, Andalusian, Roma and Latin American, but also subcultural ones – related to urban culture and the Spanish working class. Importantly, her artistic message should be analyzed both musically and visually. The text examines the relationship between local flamenco culture and popculture in the artist’s work, using the example of the song Malamente from the album El mal querer. There will also mentioned other artist’s audiovisual productions created between 2018 and 2023, which consistently build Rosalía’s musical and visual imaginary on the border of local form of expression – flamenco and global pop culture.
Skin or Skim? Inside Investment and Hedge Fund Performance
Authors: Gupta Arpit , Sachdeva Kunal
Published: July 2024

Hedge fund managers contribute substantial personal capital, or “skin in the game,” into their funds. Although these allocations may better align incentives, managers may also strategically allocate their private capital in ways that negatively affect outside investors. We find that funds with more inside investment outperform other funds within the same family. This relationship is driven by managerial decisions to invest their own capital in their least-scalable strategies and restrict the entry of new outsider capital into these funds. Our results suggest that insider capital may work as a rent-extraction mechanism at the expense of fund participation of outside investors.

This paper was accepted by Gustavo Manso, finance.

Funding: This work was supported by Columbia University and the Leonard N. Stern School of Business, New York University.

Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2024.4984 .
A comprehensive guide to removable partial dentures. Part 1: patient selection, design principles and decision algorithms for component selection
Authors: Eachempati Prashanti , Lambourn Guy , Agarwal Himanshi , Salian Kiran Kumar Krishnappa , McColl Ewen , Nooji Devi Prasad
Published: July 2024

This two-part series provides a comprehensive guide to fabricating definitive metal partial dentures, addressing the challenges dental practitioners face in mastering prosthesis design. Part 1 explores diagnostic procedures, indications for metal partial dentures, design principles, and surveying techniques. It emphasizes the understanding of biomechanical forces and discusses design principles such as support, retention and stability, along with the components that provide these functions in a metal partial denture. Decision algorithms for selecting various components are presented to guide clinical practitioners in efficient designing. The series aims to equip dental professionals with a thorough understanding of the theoretical foundations and practical methods for effective metal partial denture fabrication.

CPD/Clinical Relevance:

This series provides essential knowledge and practical techniques for designing and fabricating effective metal partial dentures.
The unilateral sagittal split osteotomy: A useful tool in the armamentarium for deeply impacted mandibular third molars
Authors: Leader Ross , Kerai Ashwin , Wade Laura , Houghton David
Published: July 2024

The unilateral sagittal split osteotomy may not be a particularly popularized method to access and remove impacted mandibular third molars (M3Ms). However, in unusual cases of deep impaction, it can provide a surgical option that minimizes bone removal and may reduce the risk of iatrogenic mandibular fracture and inferior alveolar nerve (IAN) injury, depending on the position of the third molar relative to the neurovascular bundle.

CPD/Clinical Relevance:

The unilateral sagittal split osteotomy may present an alternative method for removing impacted mandibular third molar teeth in certain situations.
The rehabilitation of a combined mid-facial defect using a magnetretained intra- and extra-oral prosthesis: a case report
Authors: Hawrot Hollie , Jablonski Rachael Y , Ali Zaid
Published: July 2024

There are several treatment options available to restore function and appearance in patients with combined mid-facial defects. Owing to the size of the defect and the associated size and weight of the prostheses, adequate retention can be challenging to achieve. Retention of a facial prosthesis can be improved using several techniques, such as medical grade adhesives, attachments, or osseo-integrated implants. For patients with a history of radiotherapy, surgical rehabilitation may be less favourable than non-surgical approaches owing to the risk of osteoradionecrosis and a reduced blood supply in the surgical fields. This clinical case report highlights the conservative rehabilitation of a combined mid-facial defect using a magnet-retained intra-oral and extra-oral prosthesis.

CPD/Clinical Relevance:

A thorough medical and clinical assessment will highlight factors that will influence the treatment planning process when managing a combined mid-facial defect.
Augmented and virtual reality in dentistry: an introduction
Authors: Slaymaker Jack
Published: July 2024

This report introduces the reader to the concepts and applications of augmented and virtual reality in dentistry. Virtual reality (VR) is the computer-generated three-dimensional simulation of a virtual environment accessed through a headset. Augmented reality (AR) is the superimposition of computer-generated imagery or graphics onto the real world, accessed through phones, tablets and headsets. The technology has advanced in recent years with early applications to the medical field revolving around anxiety management, teaching and surgical planning. Uses for surgical orthognathic and other restorative interventions are also in an early phase of development and adoption.

CPD/Clinical Relevance:

VR and AR have promising applications, but more research must be carried out to determine the technology's validity in dentistry.
Exploring machine learning approaches for early diabetes risk prediction: A comprehensive examination of health indicators and models
Authors: Panda Nihar Ranjan ,   Department of Medical Research, IMS & SUM Hospital, SOA Deemed to be university, Bhubaneswar, Odisha, India, Mohanty Jatindra Nath , Bhuyan Ruchi , Raut Prasanta Kumar Raut , - Manulata ,   School of Basic and Applied Science, Centurian University of Technology & Management, Bhubaneswar, Odisha, India,   Department of Medical Research, IMS & SUM Hospital, SOA Deemed to be university, Bhubaneswar, Odisha, India,   Trident academy of technology, Bhubaneswar, Odisha, India,   All India Institute of Medical Science, Bibinagar, India
Published: July 2024

Background: The increased prevalence of morbidity and mortality associated with Type 2 diabetes is due to changing lifestyles, demanding improved disease management measures. To tackle this, scientists are increasingly looking to technological advances, notably machine learning, for illness prevention and management, particularly in non-communicable diseases. The emphasis is on establishing an early detection system to identify Type 2 diabetes risk factors, enabling prompt treatments and preventative steps to reduce the disease’s rising prevalence. Materials and methods: The research aimed to assess the association of diabetes class with health indicators. Five machine learning models were employed with cross-validation techniques to predict early diabetes risk. The performance matrices of the models were evaluated and compared with the existing work. Results: In multivariate analysis, we found polyuria (β=3.492; Aor=32.872; 95% CI=11.09,97.35; p<0.001), polydipsia (β=-4.100; Aor=60.378; 95%CI=18.28,199.37; p<0.001), polyphagia (β=1.181; Aor=3.25; 95%CI=1.23,8.57; p=0.017), genital thrush (β=1.08; Aor=2.96; 95%CI=1.26,7.53; p=0.023), irritability (β=2.28; Aor=9.82; 95%CI=3.41,28.26; p<0.001), and partial paresis (β=1.2406; Aor=3.45; 95% CI=1.35,8.79; p=0.009) are the potential health risk indicators for positive diabetes class. Conclusion: Using an interpretable feature learning approach for early diabetes prediction improves the use of global health data. This method forecasts hazards correctly and gives insights into influential aspects. As a result, a more proactive healthcare strategy is implemented, allowing for more prompt treatments and encouraging a more hopeful future by improving patient outcomes and lowering the total burden of diabetes on individuals and healthcare systems.
INTRAOPERATIVE USE OF DEFENSIVE ANTIBACTERIAL COATING (DAC) FOR COMPLEX SURGERIES IN COMPLEX HOSTS
Authors: Roberts R. H. R. , Shams N. , Ingram-Walpole S. , Barlow D. , Syed A. , Joshi Y. , Malek I.
Published: July 2024

Periprosthetic joint infections (PJIs) and osteosynthesis-associated infections (OSIs) present significant challenges in trauma and orthopaedic surgery, substantially impacting patient morbidity, mortality, and economic burden. This concern is heightened in patients with pre-existing comorbidities, such as diabetes mellitus, which are not always modifiable at presentation. A novel intraoperative strategy to prevent these infections is the use of Defensive Antibacterial Coating (DAC), a bio-absorbable antibiotic-containing hydrogel applied to implant surfaces at implantation, acting as a physical barrier to prevent infection.

The purpose of this study is to assess the use of a commercially available hydrogel (DAC), highlighting its characteristics that make it suitable for managing PJIs and OSIs in orthopaedics and traumatology. Twenty-five patients who underwent complex orthopaedic procedures with intraoperative application of DAC between March 2022 and April 2023 at a single hospital site were included. Post-operative assessment encompassed clinical, laboratory, and radiographic examinations.

In this study, 25 patients were included, with a mean age of 70 ± 14.77 years and an average ASA grade of 2.46 ± 0.78. The cohort presented an average Charleston Comorbidity score of 5.45 ± 2.24. The procedures included 8 periprosthetic fractures, 8 foot and ankle surgeries, 5 upper limb surgeries, and 4 elective hip and knee surgeries. Follow-up assessments at 6 weeks and 6 months revealed no evidence of PJI or OSI in any patients, nor were any treatments for PJI or OSI required during the interim period.

DAC demonstrated efficacy in preventing infections in high-risk patients undergoing complex orthopaedic procedures. Our findings warrant further investigation into the use of DAC in complex hosts with randomized control trials.
TOTAL HIP ARTHROPLASTY IN PAGET'S DISEASE: COMPARISON OF OUTCOMES AFTER CEMENTED VERSUS UNCEMENTED ARTHROPLASTY. A SYSTEMATIC REVIEW AND META-ANALYSIS
Authors: Mohammed F. , Jones S. , Mansoor Z. , Mehta S. , Rathore S. , Azam A.
Published: July 2024

Paget's disease of bone (PDB) is characterised by increased bone resorption and development of an erratic bone structure that is highly fragile and susceptible to fracture. In addition, altered joint biomechanics lead to arthritis, more often in the hip and pelvis, resulting in disability and a Total hip Arthroplasty (THA) may be required. THA in PDB is associated with more complications compared to normal population. There is no consensus on the type of arthroplasty that performs better in people with PDB. To our knowledge, there is no meta-analysis in literature on this rare problem.

We undertook a systematic review and meta-analysis to compare the effectiveness of cemented versus cementless THA in patients with PDB. PRISMA guidelines were followed. Search strings were generated based on Boolean operators for identification of the reference articles.

31 studies were included overall. Revision rate was lower in the cementless group compared to the cemented group (chi square=4.36, p=0.04), aseptic loosening was lesser in the cementless group compared to the cemented group (chi square=4.13, p=0.04). The type of the arthroplasty did not affect the infection rate (chi square=2.51, p=0.11), pre and post op Harris Hip Score showed statistically significant difference, but there was no difference between types of arthroplasty

We conclude that THA with uncemented components is better and provided lower revision and aseptic loosening when compared to cemented groups in patients with PDB.
COMPLIANCE WITH THE SUSPECTED CAUDA EQUINA SYNDROME (CES) PATHWAY IN BETSI CADWALADR UNIVERSITY HEALTH BOARD (BCUHB) WEST: A RETROSPECTIVE AUDIT AGAINST NATIONAL STANDARDS
Authors: Jackson B. , Wilson C. , Blocker O.
Published: July 2024

Objective

Guidelines published by the British Association of Spine Surgeons (BASS) and Society of British Neurological Surgeons (SBNS) recommend urgent MRI imaging and intervention in individuals suspected of having CES. The need for an evidence based protocol is driven by a lack of 24/7 MRI services and centralisation of neurosurgery to tertiary centres, compounded by CES's significant medico-legal implications. We conducted an audit to evaluate the pathway for suspected CES in BCUHB West between 2018 and 2021.

Methods

A retrospective audit of patients managed for suspected CES between 01/11/2018 and 01/05/2021 was performed, using the SBNS/BASS guidelines as the standard.

Results

A total of 252 patients received an emergency MRI for suspected CES between 2018 and 2021. 99% of patients were scanned in compliance with SBNS/BASS standards. Radiological evidence of CES was found in 18% of patients. 33% of emergency scans were performed by out-of-hours services. 4% of patients had repeated scans within the same 6-month period. The majority of referrals originated from Orthopaedics surgeons (78%), or staff in the Emergency Department (8%). 92% of ambulatory patients were not admitted to hospital. During the peak of the COVID-19 pandemic, referrals increased from 2.5 to 3.5 per week.

Conclusion

SBNS/BASS standards were largely met, avoiding life changing disability and medico-legal consequences. The department should continue to follow SBNS/BASS guidance on the management of individuals with suspected CES. Challenges regarding the use of repeated scans should be addressed to avoid unnecessary costs. Introduction of new early recognition guidelines and Same Day Emergency Care (SDEC) has likely driven an increase in suspected CES referrals, and subsequent MRI demand. This audit should be utilised as an ongoing tool to ensure best practice continues, and to implement simple measures which may improve compliance with the pathway.
COMPARATIVE STUDY BETWEEN THE FAILURE RATES OF THE TROCHANTERIC FIXATION NAIL-ADVANCED (TFNA) AND GAMMA NAILS IN PROXIMAL FEMUR FRACTURE FIXATION
Authors: Sarhan M. , Moreau J. , Francis S. , Page P.
Published: July 2024

Hip fractures frequently occur in elderly patients with osteoporosis and are rapidly increasing in prevalence owing to an increase in the elderly population and social activities. We experienced several recent presentations of TFNA nails failed through proximal locking aperture which requires significant revision surgery in often highly co-morbid patient population.

The study was done by retrospective data collection from 2013 to 2023 of all the hip fractures which had been fixed with Cephalomedullary nails to review and compare Gamma (2013–2017) and TFNA (2017–2023) failure rates and the timing of the failures. Infected and Elective revision to Arthroplasty cases were excluded.

The results are 1034 cases had been included, 784 fixed with TFNA and 250 cases fixed Gamma nails. Out of the 784 patients fixed with TFNA, 19 fixation failed (2.45%). Out of the 250 cases fixed with Gamma nails, 15 fixation failed (6%). Mean days for fixation failure were 323 and 244 days in TFNA and Gamma nails respectively.

We conclude that TFNA showed remarkable less failure rates if compared to Gamma nails. At point of launch, testing was limited and no proof of superiority of TFNA over Gamma nail. Several failures identified with proximal locking aperture in TFNA which can be related to the new design which had Substantial reduction in lateral thickness at compression screw aperture.
Recognition of informal carers: a solidarity-based approach
Authors: Głos Aleksandra
Published: July 2024

This article analyses the relevance of the ethics of solidarity for unpaid care and discusses its implications for public health policy. It combines philosophical and health-policy-oriented methodologies and claims that solidarity obliges us not only to care for the most vulnerable populations but also to care with those who care. Both draw attention to the work of carers, who, despite their indispensable contribution, are notoriously invisible to healthcare systems. The article argues for their threefold recognition: as partners in healthcare provision; as co-citizens and employees with special needs; and as a potentially vulnerable population themselves.
Peer support for people with dementia: an exploratory study of two peer support models
Authors: Barcenilla-Wong Annica L. , Skaf Raquel , Hancock Nicola , Low Lee-Fay
Published: July 2024

In this article, perceived benefits, facilitators and challenges of peer support offered for and by people living with dementia are explored by comparing peer support provided by Dementia Lifestyle Coach (DLC) and Dementia Alliance International (DAI). Semi-structured interviews were conducted with interviewees from DLC and DAI. Interview recordings were transcribed verbatim and thematically analysed. Peer support offered by DLC and DAI provided connection and emotional and informational support and promoted living well with dementia. Each programme had unique barriers and facilitators. The article concludes that peer support for and by people living with dementia should be considered in post-diagnostic dementia support programmes.
Ageing, consumption and middle-classness: implications for intergenerational relations in India
Authors: Samanta Tannistha
Published: July 2024

In this piece, I use consumption as a lens to argue how urban, middle-class Indians in their middle and later ages are emerging as a distinctive consumer society while rewriting the scripts of growing old in India. This cultural shift is happening at a time when novel modes of ageing are imagined against the backdrop of transnational family arrangements, market-based care and a quest for vitality and autonomy among older Indians, altering the cultural continuities of intergenerational relationships. I show how consumption as a cultural force both expands the expressive capabilities of older persons but, at the same time, imposes disciplinary discourses around the family and social relationships. Overall, I critically reflect on what the ‘downward blurring’ of the ageing self does to the contemporary frameworks of intergenerational relationships in India. I conclude by discussing both the possibility and the (cultural) limit of theories developed in the industrialised West to capture the shifting realities of transitional societies.
Biblioteques, editorials i llibreries (2020-2022): crisi i nous reptes
Authors: González Cuadra Francesc Xavier
Published: July 2024

El trienni 2020-2022 ha estat un període excepcional per a les biblioteques, les editorials i les llibreries, així com per a la resta de l’ecosistema llibre i el món de la cultura. La pandèmia de la COVID-19 i els seus efectes han influït arreu, i especialment en l’àmbit de la informació, la cultura i el coneixement.Les noves tendències en l’accés i el consum culturals que s’albiraven al bienni 2018-2019 han experimentat un impuls exponencial. Les biblioteques digitals, l’accés obert, la socialització virtual de la lectura i, ara, la intel·ligència artificial han deixat de ser mers projectes o quimeres per esdevenir nous paradigmes de la quotidianitat en el sector bibliotecari, i en les relacions d’aquest sector amb la resta d’agents de la cultura i el coneixement. El retorn gradual a la normalitat postpandèmica ha plantejat nous reptes i la urgència de confluir amb les necessitats socials i evolucionar en els seus papers tradicionals.
Efectos de la musicoterapia neurológica en personas con demencia grave: estudio piloto
Authors: Forn Villanova Lourdes , Muñiz Sergi , Farràs-Permanyer Laia , Alavedra Cristina , Signo Sara , Bruna Olga
Published: July 2024

Antecedentes: La Musicoterapia Neurológica (MTN) se ha desarrollado durante las últimas décadas como una disciplina estructurada, basada en la evidencia y con bases teóricas surgidas de estudios neurocientíficos. Se aplica a Personas con Demencia Grave (PcDG)  para estimular funciones cognitivas y mejorar el estado emocional y conductual. Objetivos: estudiar los efectos cognitivos, emocionales y conductuales de la MTN en PcDG e introducir el uso de la escala de musicoterapia validada al español: Music in Dementia Assessment Scale (MiDAS-ESP).  Método: Estudio cuasi experimental de medidas repetidas pre-post con un grupo experimental de 30 personas. Se registraron variables sociodemográficas, clínicas, cognitivas, de comportamiento, emocionales y de calidad de vida. La intervención consistió en 10 sesiones de MTN,  realizada por un musicoterapeuta acreditado. Resultados: Se objetivaron diferencias estadísticamente significativas entre las puntuaciones registradas antes y después de la intervención, indicando mejoría emocional, comportamental y de calidad de vida. No se encontraron diferencias estadísticamente significativas en cognición global, a pesar de observar mejoría. Se objetivaron diferencias significativas en la escala MiDAS-ESP, mostrando incremento de satisfacción durante la terapia. Conclusiones: La MTN contribuye positivamente a mejorar el estado de ánimo, el comportamiento, la calidad de vida y la satisfacción en PcDG.