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The aim of this paper is to evaluate the effectiveness of The Leadership Program's Violence Prevention Project (VPP) – a 12‐session programme consisting of explicit curriculum‐based classroom instruction designed for adolescents to promote a range of communication skills associated with violence prevention and alter classroom norms about aggression and violence.

A multi‐site, quasi‐experimental effectiveness trial examined pre‐ and post‐implementation surveys that assessed violence‐related behaviours and attitudes from 3,264 6th‐8th grade students in 24 urban public schools across four consecutive academic years (2005‐2009).

Multilevel modelling showed VPP buffered negative beliefs and behaviour in a wide range of violence‐related outcomes including peer support and tolerance for aggression. VPP also promoted positive conflict resolution skills by reducing the use of verbally and physically aggressive resolution strategies over time in programme participants. Programme quality was maintained through a five point practitioner‐created fidelity system amenable to real‐world conditions.

Findings indicate semester‐long violence prevention programmes promoting communication skills are effective with urban early adolescents.

Although ceramic additive manufacturing (AM) could be used to fabricate complex, high-resolution parts for diverse, functional applications, one ongoing challenge is optimizing the post-process, particularly sintering, conditions to consistently produce geometrically accurate and mechanically robust parts. This study aims to investigate how sintering temperature affects feature resolution and flexural properties of silica-based parts formed by vat photopolymerization (VPP) AM.

Test artifacts were designed to evaluate features of different sizes, shapes and orientations, and three-point bend specimens printed in multiple orientations were used to evaluate mechanical properties. Sintering temperatures were varied between 1000°C and 1300°C.

Deviations from designed dimensions often increased with higher sintering temperatures and/or larger features. Higher sintering temperatures yielded parts with higher strength and lower strain at break. Many features exhibited defects, often dependent on geometry and sintering temperature, highlighting the need for further analysis of debinding and sintering parameters.

To the best of the authors’ knowledge, this is the first time test artifacts have been designed for ceramic VPP. This work also offers insights into the effect of sintering temperature and print orientation on flexural properties. These results provide design guidelines for a particular material, while the methodology outlined for assessing feature resolution and flexural strength is broadly applicable to other ceramics, enabling more predictable part performance when considering the future design and manufacture of complex ceramic parts.

This paper aims to investigate the influence of post-curing temperature, post-curing time and gamma ray irradiation dose upon the tensile and compressive mechanical properties of the medical graded vat photopolymerization parts.

Medical graded vat photopolymerization specimens, made from photopolymer resin, were fabricated using bottom-up vat photopolymerization machine. Tensile and compressive tests were conducted to assess the mechanical properties. The specimens were categorized into uncured and post-curing groups. Temperature post-processing and/or gamma irradiation exposure were for post-curing specimens. The post-curing parameters considered included temperature levels of 50°C, 60°C and 70°C, with 1, 2, 3 and 4 h periods. For the gamma irradiation, the exposure doses were 25, 50, 75 and 100 kGy.

Post-curing improved the mechanical properties of medical graded vat photopolymerization parts for both tensile and compressive specimens. Post-curing temperature greater than 50°C or a prolonged post-curing period of more than 1 h made insignificant changes or deterioration in mechanical properties. The optimal post-curing condition was therefore a 50°C post-curing temperature with 1 h post-curing time. Exposure to gamma ray improved the compressive mechanical properties, but deteriorated tensile mechanical properties. Higher gamma irradiation doses could decrease the mechanical properties and also make the part more brittle, especially for doses more than 25 kGy.

The obtained results would be beneficial to the medical device manufacturer who fabricated the invasive temporary contact personalized surgical instruments by vat photopolymerization technique. In addition, it also raised awareness in excessive gamma sterilization in the medical graded vat photopolymerization parts.

The industrial application of continuous glass fabric-reinforced polymer composites (GFRPCs) is growing; however, the manufacturing boundedness of complex structures and the high cost of molds restrict their use. This research proposes a three-dimensional (3 D) printing process for GFRPCs that allows low-cost and rapid fabrication of complex composite parts.

The composite is manufactured using a digital light processing (DLP) based Vat-photopolymerization (VPP) process. For the composites, suitable resin material and glass fabrics are chosen based on their strength, stiffness, and printability. Jacob's working curve characterizes the curing parameters for adequate adhesion between the matrix and fabrics. The tensile and flexural properties were examined using UTM. The fabric distribution and compactness of the cured resin were analyzed in scanning electron microscopy.

The result showed that the object could print at a glass fabric content of 40 volume%. In DLP-based VPP printing technology, the adequate exposure time was found to be 30 seconds for making a GFRPC. The tensile strength and Young's modulus values were increased by 5.54 and 8.81 times, respectively than non-reinforced cured specimens. The flexural strength and modulus were also effectively increased to 2.8 and 3 times more than the neat specimens. In addition, the process is found to help fabricate the functional component.

The experimental procedure to fabricate GFRPC specimens through DLP-based AM is a spectacular experimental approach.

Past research demonstrated that novel IT-based business models generate tremendous returns for innovators. However, the risks associated with these innovations remain under-explored. This paper aims to address this critical gap analyzing risks and offering important insights particularly for practitioners.

The authors adopted an exploratory multiple-case study research design. It draws on 22 semi-structured interviews with managers from leading energy utilities, as well as leading providers of virtual power plants technology within the German energy industry.

The research reveals that main risks in new digital business models in the energy sector are associated with three forms of interdependence between innovation actors: the regulatory, the technological and the collaborative. To deal with these interdependencies, the authors propose an original multi-step risk management framework. This framework considers the outreach as a critical dimension for risk assessment and offers a new risk response matrix to draw individual and collective mitigation activities for specific types of risks.

This paper offers a framework for the management of interdependence risks that are fundamental for business model innovations based on IT. Thus, it is applicable in companies both inside the energy sector and beyond.

This paper analyzes an important digital business model innovation that has not yet been explored in management literature – the virtual power plant (VPP). It is based on original and current empirical work and proposes a novel risk management framework for business organizations.

The purpose of this paper is to clarify the status of Maxwell's tensor with respect to the virtual power principle (VPP).

Mathematical analysis is employed.

The VPP, logically stronger, is more fundamental. Maxwell's tensor derives from it, under further restrictive assumptions, and hence, its range of applicability is limited. In particular, it fails to deal with some aspects of magnetostriction.

The paper shows that when magnetic constitutive laws depend, locally, on strain, the body force is not, as a rule, the divergence of the Maxwell tensor. People who intend to compute forces this way should be wary of that.

This study aims to form a new concept of power-to-gas-based virtual power plant (GVPP) and propose a low-carbon economic scheduling optimization model for GVPP considering carbon emission trading.

In view of the strong uncertainty of wind power and photovoltaic power generation in GVPP, the information gap decision theory (IGDT) is used to measure the uncertainty tolerance threshold under different expected target deviations of the decision-makers. To verify the feasibility and effectiveness of the proposed model, nine-node energy hub was selected as the simulation system.

GVPP can coordinate and optimize the output of electricity-to-gas and gas turbines according to the difference in gas and electricity prices in the electricity market and the natural gas market at different times. The IGDT method can be used to describe the impact of wind and solar uncertainty in GVPP. Carbon emission rights trading can increase the operating space of power to gas (P2G) and reduce the operating cost of GVPP.

This study considers the electrical conversion and spatio-temporal calming characteristics of P2G, integrates it with VPP into GVPP and uses the IGDT method to describe the impact of wind and solar uncertainty and then proposes a GVPP near-zero carbon random scheduling optimization model based on IGDT.

This study designed a novel structure of the GVPP integrating P2G, gas storage device into the VPP and proposed a basic near-zero carbon scheduling optimization model for GVPP under the optimization goal of minimizing operating costs. At last, this study constructed a stochastic scheduling optimization model for GVPP.

To foster the grid integration of both electric vehicles (EV) and renewable generators, the purpose of this paper is to investigate the possible synergies between these players so as to jointly improve the production predictability while ensuring a green mobility. It is here achieved by the mean of a grid commitment over the overall power produced by a collaborative system which here gathers a photovoltaic (PV) plant with an EV fleet. The scope of the present contribution is to investigate the conditions to make the most of such an association, mainly regarding to the management strategies and optimal sizing, taking into account forecast errors on PV production.

To evaluate the collaboration added value, several concerns are aggregated into a primary energy criterion: the commitment compliance, the power spillage, the vehicle charging, the user mobility and the battery aging. Variations of these costs are computed over a range of EV fleet size. Moreover, the influence of the charging strategy is specifically investigated throughout the comparison of three managements: a simple rule of thumb, a perfect knowledge deterministic case and a charging strategy computed by stochastic dynamic programming. The latter is based on an original modeling of the production forecast error. This methodology is carried out to assess the collaboration added value for two operators’ points of view: a virtual power plant (VPP) and a balance responsible party (BRP).

From the perspective of a BRP, the added value of PV-EV collaboration for the energy system has been evidenced in any situation even when the charging strategy is very simple. On the other hand, for the case of a VPP operator, the coupling between the optimal sizing and the management strategy is highlighted.

A co-optimization of the sizing and the management of a PV-EV collaborative system is introduced and the influence of the management strategy on the collaboration added value has been investigated. This gave rise to the presentation and implementation of an original modeling tool of the PV production forecast error. Finally, to widen the scope of application, two different business models have been tackled and compared.

The purpose of this paper is to evaluate the influence of layer thickness and post-curing temperature on shape memory properties in components manufactured by stereolithography.

Layer thicknesses of 20 and 100 µm and 22 and 45°C for post-curing temperature were selected following the design of experiments approach. Tensile and bending tests were applied for quantitative evaluation of the shape memory effect (SME). Qualitative analysis was performed using complex geometries and computed tomography as a measurement tool. Additionally, the degree of photopolymerization and glass transition temperature (T_g) were evaluated.

The tensile test resulted in fixity and recovery ratio values close to 100%. In bending, they varied between 97%–111% for fixity and 88%–95% for recovery. The layer thickness was found to have a higher influence on the SME. In complex structures, SME was dependent on geometry and less sensitive to variation in process parameters. The post-curing temperature had a higher influence on the photopolymerization and T_g. Average T_g of 77.5°C was achieved at 45°C, compared to 73.1°C at 22°C.

In the current state of the art in the processing of shape memory polymers with vat photopolymerization typically, the chemical composition or the thermal and deformation patterns are studied. The effect of the processing parameters is, however, not explored. This paper aims to close the research gap and facilitate the process optimization towards high fixing and recovery characteristics.

This paper presents an experimental investigation of photovoltaic (PV) properties in heterostructures consisting of indium oxide and amorphous silicon thin films, grown on a single crystalline p-type silicon and polyimide flexible substrates. Both thin films: In₂O₃ and a-Si were deposited by magnetron sputtering. Such heterostructure thin film systems are attractive because of their ability to convert solar energy into electrical one. Grown Heterostructures films were treated by simultaneous influence of an electron beam and high energetic photons with energy more than 1.5 eV in the so called vacuum photo-thermal processing (VPP).

Silicon samples of 100 Ω/sq and 45 Ω/sq were selected as substrates. Thin films deposition was done in argon atmosphere by DC magnetron sputtering.

It is shown that:

Open circuit voltage of the proposed structure may reach up to ~ 0.35 V,

Short circuit current was of no more then 10-7 A,

Polyimide materials may be used as substrates for PV thin film deposition structures,

VPP dramatically varies the photovoltaic properties of the heterostructure