Frequency Dielectric Spectroscopy and Dissipation Factor Measurements during Thermal Cycles on Different Types of MV Cable Joints

Results of periodic measurements of Dissipation Factor (DF) and Frequency Dielectric Spectroscopy (FDS) on Medium Voltage (MV) cables during thermal cycles, are reported and discussed in this paper. Twelve cables equipped with different types of joints were connected together to form a ring in short-circuit. The ring was energized at rated voltage and current. Temperature cycles with a period of one day (11 hours of heating) were applied by controlling the current. Periodically, each cable was tested separately using both DF and FDS techniques to monitor the ageing progression. This paper focuses on the experimental results obtained testing six new cables provided by different types of new joints while the other six coming from the field, are not considered here. Results obtained testing the six new cables indicate that FDS evaluation is a reliable tool to distinguish the aging progression of the insulation from the seasonal and reversible changes while DF values recorded at different voltage levels show a non-regular behavior particularly in XLPE cables. These results clearly suggest that the systematic use of FDS in condition assessment of underground cables can provide more information on the ageing progression than the traditional DF measurements

Self-rated health implications of noise for open-plan office workers: An overview of the literature

In open-plan offices (OPO), workspaces without ground-to-ceiling dividers, noise is one of the most complained about aspects, causing physical and psychological impacts. With the increasing interest for a human-centric design, notably after the publication of ISO 22955, this review aims to identify the main noise sources in this office layout and the employees’ perception of related health effects, evaluating the interventions proposed to overcome their impacts. Following the PRISMA guidelines, a review was conducted using the Scopus and PubMed databases, considering subjective questionnaires distributed in offices, which could include physical workspace assessment. It excluded studies limited to: (a) laboratory experiments; (b) isolated cognitive tests; (c) office layouts other than OPO; (d) systematic reviews; and (e) mathematical models. Sixty studies were identified and the screening process resulted in 11 selected for inclusion, which indicated irrelevant speech, chatting, and telephone ringing as the main noise sources causing productivity loss, stress, and low comfort rates due to distraction and lack of privacy. To overcome these impacts, researchers suggested the use of sound-absorbing surfaces, separated zones for different tasks and headphones, although their effectiveness relies on human behaviour and economic feasibility. Thus, the evidence indicates that noise is a recurrent issue in OPOs, it demonstrates the importance of appropriate acoustic performance of the workspace and the necessity of new studies regarding OPO workers’ perception of noise and their health, particularly after the COVID-19 new safety guidelines

DIAGNOSTIC TECHNIQUES OF MV CABLE JOINTS UNDER DIFFERENT ENVIRONMENTAL CONDITIONS

The article reports the results and the advances of the experimentation in progress at the RSE laboratories for a diagnostic analysis of the causes of failures that affect MV cable joints, especially during the summer periods. To this purpose two different ad hoc experimental set-ups, consisting of cables equipped with different types of joints to form a ring in short-circuit, have been realized. The rings, energized at rated voltage, are loaded with current to reproduce the daily load variation typical of a MV cable network. The first set-up simulated the reduced thermal conductivity of the soil during summer periods and the second, now under test, allows to simulate, in a controlled way, the presence of rain, even of considerable intensity

Organic Amendments to Short Rotation Coppice (SRC) Plantation Affect Species Richness and Metal Accumulation of Spontaneously Growing Herbaceous Plants

Excess potentially toxic metals (PTMs) in soils require ad hoc approaches to salvage. Hence, this study explored the shoot accumulation of cadmium (Cd), lead (Pb), and zinc (Zn) by herbaceous plants growing under previously established Salix and Populus clones Short Rotation Coppice (SRC) with compost and sewage sludge applications in an abandoned metallurgical site, Podlesí, Czech Republic; PTM decontamination of soils. Soils within the SRC experimental site and outside considered as control were analyzed for their chemical properties by multi-analytical techniques. Shoots of spontaneously growing herbaceous plants under trees in the site and without trees in control were determined for pseudo-total Cd, Pb, and Zn contents. Moderately to slightly acid soils, high cation exchange capacity, and C/N ratio supported mineralization and relative mobility of total Cd (7.7–9.76), Pb (1541–1929), and Zn (245–320 mg kg−1) in soils. Although soil amendments improved chemical properties, compost application supported higher species richness than sewage sludge. Over 95% of plants accumulated Cd and Zn above the WHO threshold and green fodder in the Czech Republic, with 36% Pb above the regional limit (40 mg kg−1). Approximately 100, 50, and 6% of herbaceous species had Cd, Pb, and Zn accumulation, respectively, higher than published average upper limits in plants (0.2 Cd, 10 Pb, and 150 Zn mg kg−1). Dicots recorded higher Cd content, Tenacetum vulgare (L.), Hypericum maculatum (Crantz), and Cirsium arvense (L.); Stachys palustris (L.), Lamium perpereum (L.), and Campanula patula (L.) for Pb; Glechoma hederaceae (L.), C. patula, and C. arvense for Zn in all treatments. Appropriate soil amelioration of SRC-supported PTM mobility and excess herbaceous species shoot accumulation, growth, and richness

Closed cannulation of subclavian vein vs open cut-down of cephalic vein for totally implantable venous access port (TIVAP) implantation: protocol for a systematic review and proportional meta-analysis of perioperative and postoperative complications

Background: Totally implantable venous access port (TIVAP) implantation is one of the most often performed operations in general surgery (over 100,000/year in Germany). The two main approaches for TIVAP placement are insertion into the cephalic vein through an open cut-down technique (OCD) or closed cannulation technique of the subclavian vein (CC) with Seldinger technique. Both procedures are performed with high success rates and very low complication frequencies. Because of the low incidence of complications, no single interventional trial is able to report a valid comparison of peri- and postoperative complication frequencies between both techniques. Therefore, the aim of this systematic review is to summarize evidence for peri- and postoperative complication rates in patients undergoing OCD or CC. Methods/Design: A systematic literature search will be conducted in The Cochrane Library, MEDLINE, and Embase to identify randomized controlled trials (RCTs), observational clinical studies (OCS), or case series (CS) reporting peri- and/or postoperative complications of at least one implantation technique. A priori defined data will be extracted from included studies, and methodological quality will be assessed. Event rates with their 95% confidence intervals will be derived taking into account the follow-up time per study by patient-months where appropriate. Pooled estimates of event rates with corresponding 95% confidence intervals will be calculated on the base of the Freeman-Tukey double arcsine transformation within a random effect model framework. Discussion: The findings of this systematic review with proportional meta-analysis will help to identify the procedure with the best benefit/risk ratio for TIVAP implantation. This may have influence on daily practice, and data may be implemented in treatment guidelines. Considering the impact of TIVAP implantation on patients’ well being together with its socioeconomic relevance, patients will benefit from evidence-based treatment and health-care costs may also be reduced. Systematic review registration PROSPERO CRD42013005180

On the electromagnetic energy resolution of Cherenkov-fiber calorimeters

Electromagnetic calorimeters which sample the Cherenkov radiation of shower particles in optical fibers operate in a markedly different manner from calorimeters which rely on the dE/dx of shower particles. The well-understood physics of electromagnetic shower development is applied to the case of Cherenkov-fiber calorimetry (also known as quartz fiber calorimetry) and the results of systematically performed studies are considered in detail to derive an understanding of the critical parameters involved in energy measurement using such calorimeters. A quantitative parameterization of Cherenkov-fiber calorimetry electromagnetic energy resolution is proposed and compared with existing experimental results

Multijet production in neutral current deep inelastic scattering at HERA and determination of α_{s}

Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson virtualities 10 5 GeV and –1 < η_{LAB}^{jet} < 2.5. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant α_{s} (M_{z}), determined from the ratio of the trijet to dijet cross sections, is α_{s} (M_{z}) = 0.1179 ± 0.0013 (stat.)_{-0.0046}^{+0.0028}(exp.)_{-0.0046}^{+0.0028}(th.)

An assay for secologanin in plant tissues based on enzymatic conversion into strictosidine

The secoiridoid glucoside secologanin is the terpenoid building block in the biosynthesis of terpenoid indole alkaloids. A method for its determination in plant tissues and in cell suspension cultures has been developed. This assay is based on the condensation of secologanin with tryptamine, yielding strictosidine, in a reaction catalysed by the enzyme strictosidine synthase (STR; E.C. 4.3.3.2). Subsequently, the formation of strictosidine is quantified by high performance liquid chromatography (HPLC). STR was isolated from transgenic Nicotiana tabacum cells expressing a cDNA-derived gene coding for STR from Catharanthus roseus. The high specificity of STR for secologanin, in combination with a sensitive and selective HPLC system, allows a simple extraction of secologanin from plant tissue. The detection limit of this method is 15 ng secologanin. Using this assay, secologanin contents were determined in tissues of various plant species; Lonicera xylosteum hairy roots were found to contain 1% of secologanin on a dry weight basis. # 1998 John Wiley & Sons, Ltd.info:eu-repo/semantics/publishedVersio

Jet production in charged current deep inelastic e⁺p scatteringat HERA

The production rates and substructure of jets have been studied in charged current deep inelastic e⁺p scattering for Q² > 200 GeV² with the ZEUS detector at HERA using an integrated luminosity of 110.5 pb⁻¹. Inclusive jet cross sections are presented for jets with transverse energies E_{T}^{jet} > 5 GeV. Measurements of the mean subjet multiplicity, 〈n_{sbj}〉, of the inclusive jet sample are presented. Predictions based on parton-shower Monte Carlo models and next-to-leading-order QCD calculations are compared to the measurements. The value of α_{s} (M_{z}), determined from 〈n_{sbj}〉 at y_{cut} = 10⁻² for jets with 25 < E_{T}^{jet} < 119 GeV, is α_{s} (M_{z}) = 0.1202 ± 0.0052 (stat.)_{-0.0019}^{+0.0060} (syst.)_{-0.0053}^{+0.0065} (th.). The mean subjet multiplicity as a function of Q² is found to be consistent with that measured in NC DIS