1,010 research outputs found
Understanding the impact of demand shocks on the container port industry
The Covid-19 pandemic has severely impacted the world economy, generating an unprecedented shock that pushed carriers to adapt to the collapse of demand. Most of the related adaptation actions (e.g., blank sailings) appear as temporary initiatives being insufficient to reach a long run equilibrium. Moreover, while carriers managed to adjust their own supplied capacity to the ongoing crisis, the port sector has been greatly impacted by the fall in transport demand, not being able to counteract the demand shortages as effectively as the carriers. Against this backdrop, the paper introduces a model for assessing the effects of demand shocks (e.g., due to the pandemic) on the integration strategies of carriers. We focus on the possible initiatives that demand shocks may trigger on the horizontal and vertical integration among the actors of the shipping industry. In doing so, the present study provides useful insights for better understanding potential future market modifications and their impact on social welfare. Using non-cooperative games, profit-maximising strategies, in case of such integrations, are compared in order to study how carriers and terminal operators might react to demand shocks in the medium and long run
A Method for the Measurement of Digitizers’ Absolute Phase Error
A lot of engineering applications, from telecommunications to power systems, require
accurate measurement of phase angles. Some of them, like synchrophasor measurement and
calibration of instrument transformers with digital output, in order to reach high phase
measurement accuracy, require the knowledge of phase error of digitizers. Therefore, in this
paper a method for the measurement of digitizers’ absolute phase errors is proposed. It adopts a
sinewave and two square waves, that are the digitizer sample clock and a phase reference signal.
Combining the measurements of the relative phase differences between the adopted signals it is
possible to accurately evaluate the absolute phase error of a digitize
Calibration of voltage and current transducers for dc railway systems
To establish a single European railway area, the European Commission requires, by 2019, that energy billings shall be computed on the actual energy consumed. So, in the near future, all the trains shall be equipped with an energy measurement system, whose measurement accuracy should be assessed and periodically reverified, as required by EN 50463-2. As for every energy and power measuring system, the voltage and current transducers play a crucial role as their accuracy could determine the performance level of the entire measurement chain. To answer to this emerging need, this paper presents a calibration system allowing the accurate testing of dc voltage and current transducers, up to 6 kV and 300 A and up to 10 kHz. It is able to reproduce all the tests prescribed by EN 50463-2, but in order to characterize the transducers in actual operating conditions, a series of additional tests can also be performed using synthetic complex waveforms or even signals acquired on-board trains. The expanded uncertainty (level of confidence 95%) of the calibration system is 43 mu extV /V and 24 mu extA /A at dc and 520 mu extV /V and 820 mu extA /A at 10 kHz. Moreover, the calibration of two commercial voltage and current transducers, currently installed in the trains of an Italian operator, is presented
Medical Waste Sorting: a computer vision approach for assisted primary sorting
Medical waste, i.e. waste produced during medical activities in hospitals,
clinics and laboratories, represents hazardous waste whose management involves
special care and high costs. However, this kind of waste contains a significant
fraction of highly valued materials that can enter a circular economy process.
To this end, in this paper, we propose a computer vision approach for assisting
in the primary sorting of medical waste. The feasibility of our approach is
demonstrated on a representative dataset we collected and made available to the
community, with which we have trained a model that achieves 100\% accuracy, and
a new dataset on which the trained model exhibits good generalization.Comment: Accepted for inclusion in IWCIM 2023 @ ICASSP2023, June 5, 2023,
Rhodes, Greec
Detection of tet(M) gene from raw milk by rapid DNA extraction followed by a two-step PCR with nested primers.
The likelihood that milk and milk products may act as a vehicle for antibiotic-resistant bacterial genes has become a concern to the food industry and a public health issue, and the demand for rapid tests has increased. The purity of DNA extracted from food samples is a key issue in the sensitivity and usefulness of biological analyses, such as PCR for pathogens and nonpathogens. A rapid, phenol-chloroform free method based on a modification of a sodium iodide DNA extraction, followed by a two-step PCR was developed for direct detection of the tet(M) gene in milk samples within a single working day. This study compares the proposed method with a traditional phenol solvent extraction method and with a commercial kit (QIAamp DNA blood mini kit, Qiagen). The three DNA extraction methods were used to ensure access to the tet(M) gene from 1 ml of raw milk, inoculated with a strain of Enterococcus faecalis, which carries the tet(M) gene. The proposed method, followed by a two-step PCR with nested primers specific for the tet(M) gene, was able to reach a detection limit below 10 CFU/ml in less than 4 h, including the two amplification cycles, thus outperforming in sensitivity and rapidity both the traditional and the commercial method
Effectiveness and safety of oxycodone/naloxone in the management of chronic pain in patients with systemic sclerosis with recurrent digital ulcers : Two case reports
Digital ulcers (DUs) are a severe and frequent clinical feature of patients with systemic sclerosis (SSc). The presence of DUs may cause severe pain and often lead to impairment of patient\u2019s functional activities and health-related quality of life. Moreover, poor patient cooperation during the wound care procedure due to pain may be associated with a negative outcome of DU healing. Therefore, pain management has a key role in patients with SSc. These two case reports describe the effectiveness and safety of oxycodone/naloxone in patients with SSc complicated by painful chronic DUs. Such a therapy has provided pain relief and consequently an increased compliance during redressing wounds
Characterization of molecular nitrogen in III-V compound semiconductors by near-edge x-ray absorption fine structure and photoemission spectroscopies
Formation of molecular nitrogen under low-energy nitrogen bombardment of III-V compound semiconductor surfaces has been studied by photoemissionspectroscopy around N 1s core-level and near-edge x-ray absorption fine structure(NEXAFS) around NK edge. Interstitial molecular nitrogen Nâ‚‚ has been formed in all of the samples under consideration. The presence of Nâ‚‚ produces a sharp resonance in low-resolution NEXAFSspectra, showing the characteristic vibrational fine structure in high-resolution measurements, and at the same time, a new peak, shifted toward higher binding energies for several eV, in all N 1sphotoemissionspectra.This work was supported by
the Australian Synchrotron Research Program, which is
funded by the Commonwealth of Australia under the Major
National Research Facilities Program, and the Research
Grant from the Ministry for Science, Education and Sport of
the Republic of Croatia
Calibration of Current Transformers in distorted conditions
In the context of modern power systems, where there are lots of non-linear loads and generators based on switching power electronics, the accurate measurement of voltage and current harmonics is a key task for the knowledge of the actual state of the network. Voltage and current transducers play a crucial role since they are always the first part of the measurement chain. Currently, classical voltage and current instrument transformers are the most installed transducers, but their performance not always is fully characterized in the presence of distorted waveforms. Therefore, in this paper a calibration setup for the accurate characterization of current transformers with distorted waveforms is presented. System implementation and characterization is presented; then it is employed for the evaluation of the performance of a commercial current transformer in distorted conditions
Calibration System for DC Power/Energy Measurement chain in Railway applications
In order to guarantee the European interoperability of rolling stock, the European Union (EU) established that all the trains shall be equipped with an Energy Measurement Function (EMF) for billing purposes. The measurement accuracy of such devices should be assessed and periodically re-verified, as required by EN 50462-2. This paper describes a setup for the calibration of combined voltage and current transducers and EMFs for on-board Direct Current (DC) train installation. The reference system is able to generate an arbitrary DC phantom power up to 6 MW with voltage up to 5 kV and a current up to 1.2 kA. Furthermore, in order to perform tests as close as possible to real operating conditions, the system allows performing dynamic tests, reproducing waveforms obtained in real measurement campaigns. The computed uncertainty for steady state tests is 0.025%, whereas the target uncertainty for dynamic tests is 0.1%. The generation system can also be applied for on-board reverification of EMF
Tryptophan Metabolism as Source of New Prognostic Biomarkers for FAP Patients
Familial adenomatous polyposis (FAP), a common inherited form of colorectal cancer (CRC), causes the development of hundreds to thousands of colonic adenomas in the colorectum beginning in early adolescence. In absence of a prophylactic surgery, FAP patients almost inevitably develop CRC by the age of 40 to 50. The lack of valuable prognostic biomarkers for FAP patients makes it difficult to predict when the progression from adenoma to malignant carcinoma occurs. Decreased tryptophan (TRP) plasma levels and increased indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan hydroxylase 1 (TPH1) enzymatic activities have been associated to tumour progression in CRC. In the present study, we aimed at investigating whether an altered TRP metabolism might also exist in FAP patients. Our results highlighted that plasma levels of TRP and its main catabolites are comparable between FAP patients and healthy subject. On the contrary, FAP patients presented significantly higher TRP levels with respect to high-grade adenoma (ADE) subjects and CRC patients. Obtained data lead us to evaluate IDO1 and TPH1 enzymes activity in the study groups. For both enzymes, it was possible to discriminate correctly between FAP subject and ADE/CRC patients with high sensitivities and specificities. By receiver operating characteristic (ROC) curve analysis, the cut-off values of IDO1 and TPH1 enzymatic activities associated to the presence of an active malignant transformation have been calculated as >38 and >5.5, respectively. When these cut-off values are employed, the area under the curve (AUC) is > 0.8 for both, indicating that TRP metabolism in patients with FAP may be used to monitor and predict the tumorigenic evolution
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