7 research outputs found
Demonstration of Feeding Vehicle-Integrated Photovoltaic-Converted Energy into the High-Voltage On-Board Network of Practical Light Commercial Vehicles for Range Extension
The setting up of a practical electrically driven light commercial demonstration vehicle with integrated photovoltaics (PV) is reported. The demonstrator vehicle is equipped with 15 modules based on the crystalline Si/amorphous Si heterojunction technology. The nominal total peak power under standard testing conditions is 2180 Wp. Specifically, the PV-converted energy is fed into the high-voltage (HV; 400 V) board-net for a utilization of the large capacity of the HV battery and thus for direct range extension. The demonstrator vehicle is equipped with irradiation, wind, temperature, magnetic, and global positioning system sensors. Irradiation and temperature as well as the energy flows from modules, maximum power point trackers (MPPTs), low-voltage buffer battery to HV battery via DC/DC, and from the HV battery to the loads during an exemplarily test drive day (May 31, 2021) are monitored. The range extension obtained at this day on our test route (51° 59′ N, 9° 31′ E) was 36 km, the corresponding CO2 savings account for ≈2.3 kg. The chain efficiency of the electronic components from the input side of the MPPTs to the HV output side of the DC/DC was 68.6%, whereas the DC/DC itself has an average efficiency of 90%. © 2021 The Authors. Solar RRL published by Wiley-VCH Gmb
Reliability study on chip capacitor solder joints under thermo-mechanical and vibration loading
In this work we present the results on a reliability study on chip capacitor solder joints. The components were tested under three different loading conditions. First, temperature shock tests were conducted on a set of various chip capacitor components. Tested components were evaluated for the occurred damage and the causing damage mechanisms. Using finite element analysis (FEA) the accumulated solder joint creep strain per cycle was determined and used to establish a life time model based on the Coffin-Manson approach. Second, another set of components was exposed to vibration loading. These components were tested in the as cast and isothermally pre-aged condition. The vibration experiments were accomplished at room and elevated temperature. The evaluation focused on the occurred damage as well as the causing damage mechanisms again. FEA was utilised to determine the maximum von Mises stress of the solder joints. Life time and stress data were merged to define the parameters for a Basquin life time model for the vibration load cases. In a third step sequential experiments were accomplished. Temperature cycling with subsequent vibration loading and vice versa was done. Observed cycles to failure were compared to the results from the temperature shock and vibration experiments. A reduction in crack initiation as well as failure cycle count was observed. The damage mechanism was studied as for the single load experiments
First Results of Peer Training for Medical Staff—Psychosocial Support through Peer Support in Health Care
Background: In view of the increasing strain on health workers, psychosocial support measures are becoming more important. The core of a sustainable concept is the establishment of peer support teams. Two aspects are central: first, target group-specific training content, and second, suitable staff members who are trained as peers. The goal of the study was to obtain a first look at what content can be taught in peer training for medical staff, how the training is evaluated by the target group, and which people are interested in training from peers. Methods: During the period 2017–2022, Peer Training for medical staff was developed by a non-profit institution in Germany with state funding and the support of a medical professional association and evaluated during the project. Participants (N = 190) in the Peer Training course were interviewed in advance about their experiences and stresses at work using an anonymous questionnaire. After completing the training modules, the participants filled out an evaluation form. Results: The participants of the Peer Training were predominantly female (70.5%) and middle-aged (between 31 and 50 years old). Most (80.3%) experienced stressful events themselves, mostly without any preparation (93.5%) or follow-up (86.8%) by the employer. The participants estimate their workload in the medium range. The proportion of stressed individuals among the participants was below that of various comparison groups as available reference values. The training module itself was evaluated very positively. Conclusions: The content and framework parameters of the training were rated very well. There is a high degree of fit with the requirements in the health sector. The participants in the Peer Training seem to represent a good cross-section of the target group medical staff, also regarding their own experiences, seem to have a good psychological constitution and are therefore very suitable to work as peers after the training
Calling for Help—Peer-Based Psychosocial Support for Medical Staff by Telephone—A Best Practice Example from Germany
Background: A telephone support hotline (PSU-HELPLINE) was established at the beginning of the pandemic due to the burden on health professionals and the lack of support at the workplace. The aim of this study was to evaluate the telephone support service for health professionals in terms of its burden, benefits, and mechanisms of action. Methods: Data collection was conducted during and after calls by PSU-HELPLINE counsellors. In addition to the socio-demographic data evaluation, burdens of the callers and the benefits of the calls were collected. The content-analytical evaluation of the stresses as well as the effect factors were based on Mayring’s (2022). Results: Most of the callers were highly to very highly stressed. The usefulness of the conversation was rated as strong to very strong by both callers and counsellors. The PSU-HELPLINE was used primarily for processing serious events and in phases of overload. The support work was carried out through the following aspects of so-called effect factors, among others: psychoeducation, change of perspective, resource activation, problem actualization, connectedness, information, problem solving, self-efficacy, and preservation of resources. Conclusions: The expansion of local peer support structures and the possibility of a telephone helpline are recommended. Further research is needed
За кадры. 1978. № 44 (2115)
Старейшая кузница инженерных кадров Сибири1. Химико-технологический 2. Инженерной химии и химической кибернетикиАвтоматика и вычислительной техникиТеплоэнергетическийГеологоразведочныйФизико-техническийЭлектро-энергетическийЭлектрофизическийМашиностроительныйМатематика / В. РожковаПонять и усвоить. Физика / Л. ГригорукУсловия прием
Effect of Polymer Molecular Weight and Solution Parameters on Selective Dispersion of Single-Walled Carbon Nanotubes
The selective dispersion of single-walled carbon nanotube
species
(n,m) with conjugated polymers such as poly(9,9-dioctylfluorene) (PFO)
and poly(9,9-dioctylfluorene-<i>co</i>-benzothiadiazole)
(F8BT) in organic solvents depends not only on the type of solvent
but also on the molecular weight of the polymer. We find an increasing
amount of nanotubes and altered selectivities for dispersions with
higher molecular weight polymers. Including the effects of different
aromatic solvents, we propose that solution viscosity is one of the
factors influencing the apparent selectivity by changing the reaggregation
rate of the single-walled carbon nanotubes (SWNT). The type of solvent,
polymer molecular weight, concentration, and viscosity should thus
be taken into account when screening for new polymers for selective
SWNT dispersion