"You can see how things will end by the way they begin". The contribution of early mutual obligations for the development of the psychological contract

This study explores dynamic processes in the development of the psychological contract, focusing on the interaction of obligations related to the two parties (i.e., employees' perceptions of both their own and the organization's obligations fulfillment) on attitudinal outcomes (organizational commitment and turnover intention) during the initial stage of the employment relationship. In a twofold cross-sectional and two-wave study on newly hired correctional police officers, we examined: (a) whether perception of organizational obligations fulfillment moderates the relationship between employee obligations and their attitudes (Study 1, n.500); (b) the direct and moderated influence of perceived obligations at the entrance stage on those in the following months (Study 2, n.223). Results confirmed that, in the eyes of the newcomer, the obligations fulfillment of each of the two parties interact, having an additional effect beyond the main direct effects, in influencing both subsequent obligations perceptions and, through this, the outcome variables. Theoretical and practical implications of the findings are discussed

Effects of LED Lights and New Long-Term-Release Fertilizers on Lettuce Growth: A Contribution for Sustainable Horticulture

The horticulture sector has been directed by European guidelines to improve its practices related to environmental sustainability. Moreover, the practice of horticulture in urban areas is increasing since it provides fresh products that are locally produced. At the same time, horticulture needs to implement circular economy approaches and energy-efficient models. Therefore, to address these issues, this study investigated the effects of an integrated fertilizer-box-based cultivation system equipped with LED lights and coated porous inorganic materials (C-PIMs), which was applied as fertilizer, on Lactuca sativa L. growth. Two different types of lightweight aggregates were formulated considering agri-food and post-consumer waste, and they were enriched with potassium and phosphorus. Involving waste in the process was part of their valorization in the circular economy. Using PIMs as fertilizers enabled the controlled release of nutrients over time. The tests were carried out in controlled conditions using two LED lighting systems capable of changing their light spectrum according to the growth phases of the plants. The effects of two different lighting schemes on the growth of lettuce plants, in combination with different amounts of aggregates, were studied. The results showed that increasing the amount of C-PIMs statistically improved the lettuce growth in terms of dry biomass production (+60% and +34% for two different types of PIM application) when the plants were exposed to the first LED scheme (LED-1). Plant height and leaf areas significantly increased when exposed to the second LED scheme (LED-2), in combination with the presence of C-PIMs in the soil. The analysis of the heavy metal contents in the lettuce leaves and the soil at the end of the test revealed that these elements remained significantly below the legislated thresholds. The experimental achievements of this study identified a new approach to improve the environmental sustainability of horticulture, especially in an urban/domestic context

Cork powdery industrial waste in metakaolin–geopolymer matrix

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Recovery of Cork Manufacturing Waste within Mortar and Polyurethane: Feasibility of Use and Physical, Mechanical, Thermal Insulating Properties of the Final Green Composite Construction Materials

The valorization of industrial waste is a hot topic toward circular economy and sustainability. Several wastes have been proposed as resources for different production processes; however, others are still disposed to landfill or waste-to-energy plants. For the first time, this work suggests a sustainable alternative to managing cork waste from bottle caps manufacturing; this is generated by a local company at about 220,000 m3/year. The powder waste has a 0.063–1 mm particle size and is mainly composed of cork, polyurethane adhesive, and paraffin. Its valorization is proposed as filler in construction materials such as lime-based mortar (1–4 wt%) and polyurethane (5–15 wt%). Thermal, spectroscopic, and physical characterizations are performed on the cork waste, and mainly result in a low apparent density (340 kg/m3) and high-water absorption (177%). Cork properties allow consideration of extra water in the mortar mix and improve lightness without significantly affecting compressive, bending strength, and thermal insulation. Cork waste in polyurethanes promotes a color change, slightly increases the density (up to 12.5%), and still results in producing a thermally insulating material (<0.06 W/mK). Considering the promising results, this study demonstrates the feasibility of using the manufacturing waste from cork bottle caps to produce green construction materials, thus upgrading it from waste to secondary raw material

Organizational capital: a resource for changing and performing in Public Administrations

The aim of this study was to deepen our knowledge about the role played by organizational capital (OC) among public administration (PA) agencies. A questionnaire was administered to a gender-balanced convenience sample of 270 workers of Italian PAs. First, confirmatory factor analysis was performed in order to examine the measurement model. Second, a SEM model was performed, confirming that OC was both directly and indirectly positively related to performance, through the mediation of innovation. OC was also positively related to innovation through the mediation of clarity about change. Overall, the results supported the hypothesized model, providing initial evidence on the pivotal role OC plays, and especially for PA agencies, on organizational innovation and performance. The limits and practical implications of these results are discussed

Statistical optimization of a sustainable fertilizer composition based on black soldier fly larvae as source of nitrogen

In the present work, a statistical optimization of a sustainable coating for core–shell NPK (Nitrogen–Phosphorus–Potassium) fertilizers was investigated. The environmental green coating was enriched in nitrogen using a biomass and renewable source, namely the nitrogen rich fraction of black soldier fly larvae (BSFL) (Hermetia Illucens, Diptera: Stratiomyidae) reared on vegetable waste. A rational approach was proposed with the aim of calculating the best formulation of the coating, considering both its manufacturing behavior, such as adhesion to the core, and its physical properties, such as homogeneity or plasticity. From a circular economy perspective, together with the nitrogen-rich fraction from BSFL (from 51 to 90 wt.%), water and glycerol were considered for the coating formulation in different proportion: from 10 to 32 wt.% and from 0 to 17 wt.% respectively. The Design of Experiments technique was implemented to limit the total number of tests for the coating formulation (18 tests). ANOVA was employed, with the aim of obtaining mathematical models to derive a better precise and objective formulation. The results show that the use of glycerol can be avoided, as well as only a limited amount of water (11 wt.%) is necessary to obtain an optimized coating formulation, thereafter, satisfying the more relevant technological and physical properties for the coating manufacturin

Recycling of Waste Corundum Abrasive Powder in Mk-Based Geopolymers

Recycling corundum abrasive powder in metakaolin-based geopolymer formulations is proposed to reduce the amount of waste to be treated or disposed of in landfills, allowing to decrease ecological damage as well as to reduce transport costs for removal. The addition of waste corundum, as an important source of Al(2)O(3), has proved to increase the slight ionic conductivity of the leachate solution obtained after immersion in water of samples at 28 d of curing at room temperature. With the same curing conditions, the geopolymerization process has not been disturbed as evidenced by the FT-IR peak shift and XRD patterns. It was recorded a decrease in resistance to compression of the consolidated geopolymers of about 5% with 10 wt% addition and of about 77% with the addition of 20 wt% of waste corundum. In any case, the waste abrasive powder does not release heavy metals when added to a geopolymeric formulation based on MK, NaOH, and Na-silicate, and does not show relevant antibacterial properties, indicating the formation of a stable and safe final product with a ceramic-like appearance

Waste Cork in Metakaolin–Geopolymer Matrix: Physico-Mechanical Characterization

Cork powdery waste (CW) from agglomerated cork caps manufacturing is commonly transported to waste-to-energy plants, although it could be locally exploited for lightweight building materials. The transformation of CW into a geopolymer formulation to obtain a novel composite formulation suitable for insulating panels is presented in this contribution. The geopolymer mix was based on metakaolin added to NaOH and Na silicate solutions, to which 2.4, 4.8 and 9.1 wt% (calculated upon dry metakaolin) of CW in the form of as-received powdery waste were added. No pre-treatments were performed on CW and no thermal curing was conducted for the alkaliactivated product that was consolidated at room temperature to improve product sustainability. The insulating panel presented an apparent density of about 1.521 to 0.990 ± 0.001 g/cm3 , combined with a total porosity in the range of 35.61 to 56.22 ± 0.003 % for 2.4 to 9.1 wt% of CW, respectively, and this was dependent upon ageing time. The values of its mechanical properties (compressive strength ranged from 2.5 to 1.5 MPa at 28 and 90 days of curing time, complying with UNI EN 998-2) and thermal insulating properties (thermal conductivity around 0.1146 W/mK) indicated that the highest percentage of CW in the formulations, i.e., 9.1 wt%, was suitable to obtain self-standing insulating panels