Initial Impulse Research Articles

A balancing act: radicality and capture in institutionalising reflexive governance for urban sustainability transitions

Over the past two decades, urban actors have sought to foster long-lasting change towards sustainability through reflexive governance. Related activities, including transition labs, arenas, experiments, and roadmaps, have been problematised for disparities between using a discourse of transformation and radicality while failing to materialise radical action and succumbing to ‘projectification’ – meaning that the impact of an intervention tends to evaporate after the initial experiment impulse. Enabling a transformative legacy of such interventions requires institutionalising reflexive governance arrangements, i.e. a process of integrating these arrangements as part of the existing institutional set-ups while maintaining ‘radical’ elements. Particularly as the focus in certain urban transitions shifts from emerging and supporting niche practices towards institutionalising new ways of working and breaking down regime structures, it becomes paramount to better understand such processes. Based on a comparative empirical analysis of six European cities, we explore how these cities attempt to institutionalise reflexive governance and take stock of the tensions encountered, particularly to what extent cities manage to safeguard their radical ambitions, or whether these become ‘captured’ in the process. Other highlighted tensions are a focus on internal dynamics, a struggle around voluntary structures and accountability, and a challenge of keeping momentum with new actor constellations while trying to address complexity and uncertainty. We conclude by putting forward three recommendations for how reflexive governance processes may increase their impact: through prioritising institutional embeddedness in and outside of the local authority; creating transparency around how governance arrangements are adjusted and modified throughout the process for accountability; and renewing commitment periodically to ensure continuity and commitment from actors involved.

Nexus Between Asset Class Volatility and the Output Gap in Nigeria: A Bayesian Var Approach

<p class="MsoNormal" style="margin-top: 12pt; text-align: justify;"><span lang="EN-US" style="font-family: 'times new roman', times, serif; font-size: 14pt;">Excessive volatility in financial markets can disrupt economic activity, affect investor and consumer confidence, and potentially lead to financial crises in an economy. Due to this backdrop, this study examined the link between asset class volatility and the output gap in Nigeria. The asset classes were categorized into stock, crude, gold, and bitcoin. The study adopted the GARCH and Bayesian VAR approach and found that all share index has an initial negative impulse with output gap while other asset classes have a positive impulse on output gap. The outcome of this study revealed to both policymakers and economists the potential risks and vulnerabilities of asset class volatility in the economy. Based on this result, recommendations are made amongst which is the strengthening of the Nigerian stock market to help with the inflationary pressures this is because the Nigerian stock market hurt the output gap also, the government should prioritize investing in crude, gold, and bitcoin to push the actual output to full capacity, which brings about employment.</span></p>

On a new structure of multi-term Hilfer fractional impulsive neutral Levin-Nohel integrodifferential system with variable time delay

<abstract><p>The Levin-Nohel equations play key roles in the interpretation of real phenomena and have interesting applications in engineering and science areas, such as mathematical physics, mathematical biology, image processing, and numerical analyses. This article investigates a new structure for the delay neutral Levin-Nohel integrodifferential (NLNID) system via a Hilfer fractional derivative and is supplemented by initial and instantaneous impulse conditions. A fractional integral equation corresponding to the proposed system is derived and used to prove the existence and uniqueness of the solution with the help of the Banach contraction principle. Additionally, the Ulam-Hyers-Mittag-Leffler (UHML) stability is studied by utilizing the generalized Gronwall's inequality and nonlinear analysis issues. As a consequence, the Ulam-Hyers (UH) stability and generalized UH are also deduced. Furthermore, the Riemann-Liouville ($ \mathcal{R.L.} $) and Caputo fractional versions of the proposed system are discussed. Finally, numerical applications supported with tables and graphics are provided to test the exactitude of the findings.</p></abstract>

“Death in his hand”

Chris Murray, “‘Death in his hand’: Theories of Apparitions in Coleridge, Ferriar, and Keats” (pp. 179–210) On a chance meeting in 1819, Samuel Taylor Coleridge told John Keats about his theory of “double touch.” This hypothesis is key to the famous accounts in which each poet mythologizes the other. In his writings on double touch, Coleridge surmises that we engage with our world simultaneously by sensory perception and an energetic connection derived from Mesmerism. Disruption to either aspect of double touch results in the pathological state of “single touch,” symptoms of which can include hallucination. Coleridge developed his theory in dialogue with physician and author John Ferriar. Each theorized that ghost-sightings occur when the mind articulates disease as strong imagery and each used literature, particularly Shakespeare’s Hamlet (1603), as a source of evidence for psychological speculations. Coleridge’s double-touch theory pervades his notebooks and his lectures on drama, and his verbal account provided Keats with a new means to explore the supernatural in narrative verse. Hence, double touch receives its most significant literary treatment in Keats’s compositions over the weeks following his conversation with Coleridge. In particular, “La Belle Dame sans Merci” (1819) proceeds from an initial impulse to parody Coleridge to a serious exploration of double touch. Conversely, Coleridge’s claim to have foretold Keats’s death is influenced by double-touch theory and “La Belle Dame sans Merci.”

Analysis of the Application of Fire Protective Composition for Wooden Structures

In construction, coniferous wood is usually used as load-bearing and enclosing structures. Wood is characterized by the ability to ignite and spread combustion when heated in air. Wooden building structures pose a fire hazard, since with an initial impulse of external thermal energy, ignition is possible. In addition, when a fire occurs in buildings and structures where wood is located, a number of dangerous fire factors arise: flames, sparks, heat flow, toxic combustion products, extremely low oxygen concentrations, decreased visibility due to smoke. In this regard, it becomes relevant to treat wood with special compounds that increase resistance to fire. The authors examined the fire hazardous properties of building structures made of wood, analyzed the fire retardant treatment of wooden structures with a special composition; examined the fire hazardous properties of building structures made of wood, the mechanism of pyrolysis, and the effect of fire retardant treatment on the behavior of wood when exposed to fire. The use of fire retardant significantly affected the pyrolysis processes of the samples. The information obtained during the study made it possible to assess the degree of differences in the values of the average weight loss of samples treated with different fire retardants. Samples using a fire retardant composition have a shallower charring depth. Damage associated with thermal exposure is fundamentally different from untreated samples. Treated and impregnated samples exhibit rapid weight loss. This is due to the fact that in treated and impregnated samples, when exposed to high temperatures in the oven, the reactions of dehydration and cross-linking of cellulose molecules are accelerated.

Dynamics of nonlinear energy sink with a polynomial damped frequency converter

In recent years, significant strides have been made in enhancing stiffness design to improve energy dissipation efficiency. Nevertheless, there appears to be limited discourse on the concept of decomposing vibrational energy into multiple frequencies to enable concurrent dissipation. This paper introduces an innovative isolator denoted as NES-C, characterized by polynomial variable stiffness, consisting of a nonlinear energy sink and a polynomial damped frequency converter (PDFC). Tristate NES-C and quad-state NES-C configurations are realized by exploiting the nonreciprocal nature of energy propagation within the PDFC framework. Numerical simulations reveal that NES-C exhibits adaptive stiffness modulation contingent upon vibration intensity, facilitates frequency decomposition, and exhibits superior damping characteristics compared to the conventional Type I NES. Investigation into the influence of various parameters on the vibration mitigation performance of NES-C reveals that quad-state NES-C exhibits heightened robustness relative to tristate NES-C, particularly in cases involving smaller initial impulses. Additionally, the amalgamated attributes of PDFC impart enhanced programmability to NES-C design.

Damage behavior and assessment of aeronautical PMMA subjected to high-velocity water-jet impact

Rain erosion of forward-facing aircraft components such as windshields can lead to a significant reduction in performance, hence a potential hazard to air safety, especially for supersonic fighters exposed to precipitation. To understand such threats, the damage behavior of two types of most commonly used aeronautical PMMA, i.e., oriented and non-oriented, under water droplet impact is investigated. A single-impact jet apparatus based on the one-stage gas gun was established to simulate the rain droplet impact. Two critical variables were evaluated, including water-jet velocities and incident angles. Typical damage characteristic features including annular depression and circumferential cracks were observed on non-oriented PMMA targets. In contrast, on oriented PMMA targets, massive subsurface craze delamination was observed without any sign of surface cracks. The distinct damage features are determined by the different damage behavior of the oriented and non-oriented PMMA targets during the initial stage of the impingement and the shearing effect of the lateral jet. Increasing impact velocity leads to surface peeling and bulk removal, escalating the damage severity. The damage mechanism of subsurface failure was revealed by observing stress wave interaction and the FEM simulation. An impulse method was developed to quantify each impact event and assess the damaged area. A linear relationship between the damaged area and the initial impact stage impulse was established, which can be applied for preliminary evaluation and prediction of the damage caused by high-velocity water droplet impact on aeronautical PMMA.

Semi-Analytical Midcourse Guidance for Coordinated Interception of Multiple Exo-Atmospheric Targets

The simultaneous interception of multiple exo-atmospheric threat targets can leave no buffer time for the targets and greatly reduces targets’ penetration probability. This paper proposes centralized and decentralized two midcourse guidance methods to solve the coordinated interception of multiple exo-atmospheric targets. First, the free-time cooperative interception problem minimizing the total impulses is established, where the nonlinear dynamics of the interceptors and targets, the initial impulse constraints, and the terminal interception constraints are considered. Second, the necessary conditions for the optimal cooperative interception problem are derived and then approximated using higher-order Taylor expansions, which result in a series of analytical nonlinear equations. Then, the semi-analytical centralized guidance mode is designed to achieve simultaneous interception of targets by directly solving the analytical nonlinear equations. To improve computational efficiency, the decentralized cooperative guidance mode is further proposed by using the developed iterative freezing trajectory method, where each interceptor uses information from other interceptors in the previous iteration for prediction and distributed computation. Numerical examples verify the effectiveness and robustness of the proposed two guidance methods. Results show that the computational efficiency of the decentralized guidance mode is more efficient compared with the centralized midcourse guidance mode.

Modal analysis of concrete filled steel tubular structure under lateral impact loading

In this paper, deformation mode and the large deflection of the concrete filled steel tubular (CFST) structural member with fixed ends under lateral impact loading was studied by rigid-plastic modal approximation method and finite element analysis by ABAQUS. Using the yield criterion and beam-on-foundation model, the modal analytical solution for plastic behavior of CFST member under lateral impact is obtained considering the interaction of bending and axial stretching. The rigid-plastic modal solution captures the FE results and the deformation mode is accordance with the available experimental results. It shows that lateral deformation of CFST member can be effective predicted by the modal solution consisting of geometric and physical parameters variations. The influence of steel tube thickness, cross-section diameter, effective length, strength and density of concrete and steel, and initial impulsive are discussed in detail. The results show that deflection of the CFST member increase with the increase of the length to diameter ratio, initial impulse and smaller thickness to diameter ratio. Finally, the relationship between lateral deformation and geometric variations are established by optimal sets of modal solution.

Bifurcation analysis of cantilever beams in channel flow

The flutter of cantilevered beams in channel flow is a benchmark example of flow-induced vibrations and its fundamental behaviour is found in numerous practical applications. Experiments have shown that such systems present a wide variety of complex nonlinear behaviour. However, the plethora of previous studies is mostly concerned with linear stability analysis. In this work, we provide an initial impulse for a comprehensive nonlinear study of these systems through bifurcation analysis. We consider a one-dimensional problem, where a cantilevered beam is treated in a modal framework and the surrounding flow is modelled by bulk-flow equations. The system is discretized in space and time via Galerkin procedures (modal, Tau and harmonic balance) and the continuation of periodic solutions is achieved using the asymptotic numerical method. Additionally, a numerical method for an “augmented” linear stability analysis is proposed, allowing the continuation of Hopf bifurcation branches, including their sub- or super-critical nature. The nonlinear dynamics are explored with respect to various dimensionless parameters. Results illustrate a number of behavioural trends: sub-critical bifurcations and hysteresis loops, internal resonances, grazing boundaries (separation between limit cycles with and without intermittent beam-wall impacts) as well as torus bifurcations and quasi-periodic oscillations.

Шоковая инновация: концептуализация процесса цифровой трансформации образования в период пандемии

The article considers the transition to distance learning in the context of COVID-19 pandemic as innovation. In particular, it shows that the spread of innovation in an extremely fast and compressed way does not fit the classical model of innovation diffusion by Rogers. Based on the results of the analysis, the authors supplement the innovation theory with a model of shock innovation which aims to describe the phenomenon of momentary transformations. For that reason, a comprehensive and extensive description of innovation diffusion was narrowed down to three key characteristics and linked to three levels (micro-, meso- and macro-). The narratives of school principals which have been extracted from the interviews (N=10) were compared with the characteristics of this three-levels model. The analysis revealed that a shock innovation is characterized by the fact that (1) the initial impulse has a source, external to the system, (2) requiring an obligatory response (forced change); (3) manifested by an innovative “breakthrough” due to the extreme mobilization of the resources; and (4) “densification” of traditional innovative processes for the diffusion of innovation at three levels - individual (micro), group (meso-) and systemic (macro-). The discussion highlights the aspects of the identified characteristics that should be taken into account in designing the strategies of schools’ development, as well as bridging the gaps in the educational system caused by the pandemic.

Značaj pojma intersekcionalnosti za socijalnu patologiju: epistemološki i metodološki aspekti

The aim of the paper is to consider the importance of intersectionality as an innovative theoretical and methodological tool for conceptualizing the social differences in the field of social pathology. In order to realize the goal set, we first approach the definition of intersectionality and its delimitation in relation to related concepts, while clarifying our own understanding of the concept, which we base on material directions within the approach of diversity politics and critical race theory. Unlike modern sociological understandings, contemporary studies of social differences theoretically rely on more complex approaches, such as constructivist interactionism, phenomenology, post-Marxism, gender studies, postcolonial studies, and critical theories of society, which focus on identity and subjectivity. The materialistic aspect of the critical approach and issues related to policies of distribution are mostly neglected, amid the dominance of the postmodernist culture of thinking, which often manifests itself as imprecise and unfounded. The initial impulse for writing this paper is precisely the effort to reanimate that repressed, material dimension. Then, the paper shows the advantages of using the intersectional approach in the research of critical analysis of public policies and critical criminology, so that the focus in the final part of the paper is directed to specific methodological topics and problems in the study of which the concept of intersectionality has proven to be important and necessary.

UHECR echoes from the Council of Giants

ABSTRACT Recent anisotropy studies of UHECR data at energies ≳40 EeV have disclosed a correlation of their angular distribution with the extragalactic local structure, specifically with either local starburst galaxies or AGN. Using Monte Carlo simulations taking into account photodisintegration processes, we further explore a framework in which these UHECRs were accelerated by Centaurus A in a recent powerful outburst before being scattered by magnetic fields associated with local, Council of Giant, extragalactic structure. We find that the observed intermediate-scale anisotropies can be accounted for by the Council of Giant structure imposing a response function on the initial outburst of UHECRs from a single source located at Centaurus A’s position. The presence of these local structures create ‘echoes’ of UHECRs after the initial impulse and focusing effects. The strongest echo wave has a lag of ∼20 Myr, comparable to the age of synchrotron-emitting electrons in the giant Centaurus A lobes. Through consideration of the composition of both the direct and echo wave components, we find that the distribution of the light (1 < ln A < 1.5) component across the sky offers exciting prospects for testing the echo model using future facilities such as Auger prime. Our results demonstrate the potential that UHECR nuclei offer, as ‘composition clocks’, for probing propagation scenarios from local sources.

The secret life of objects in the immanent art of Morandi: Or: How art shows us how to write about art if we only let it1,2

In this example of relatively long-form art writing, the writer begins by relaying an anecdote regarding a difficult interaction with an editor. As this rocks the confidence of the writer, they try to rally themselves but seeking out an almost arbitrary receptor for their art writing skills and passions. This turns out to be a concurrent exhibition of the paintings of Giorgio Morandi. The piece describes the writer’s feelings, as well as the journey to the gallery, and ultimately creates a form of review or representation of the exhibition. However, the initial impulse for the piece remains and is returned to in a series of analyses of the writer’s method. This includes a candid exploration of the writer’s considerations of the place of judgement in their own and in contemporary art writing. Ultimately, the piece toys with the idea that, in an age of ambivalence, in which judgements all too easily seem all too harsh, it might just be the use of adjectives that are sufficient to betray an art writer’s evaluation of what they are otherwise simply describing. While the initial criticism by an editor involved the concept of transcendence, the art writer takes this accusation on board and tries, again candidly, to judge themselves, and for themselves, with regard to this concept. Ultimately, they find that, far from leaning towards transcendent values in art they are in fact committed to forms of immanence. Along the way other artists, including Cezanne and De Chirico, as well as other thinkers such as Deleuze and Alfred Jarry are utilized to develop the lines of thought. Ultimately, and rather obliquely, the piece becomes a response to the editor’s riposte and appears to succeed, to some extent, in re-founding the writer’s confidence in their own methods and beliefs, to which they have been led by their own approach to art writing, and of course by the art itself.

The Pneumatology of the Synodal Church

The Pneumatology of the Synodal Church Peter Casarella I. The Voice From The Empty Chair THE GIFT AND AGENCY of the Holy Spirit are necessary for and central to a Church that aims to embark on a synodal path. The Holy Spirit guides the entire people of God, and the ecclesial discernment that allows the people to follow in the footsteps of Christ is also a product of the work of the Spirit. This recognition of a profoundly pneumatological presence of God on the path to synodality marks Pope Francis’s thought: “Synodality is an ecclesial journey whose soul is the Holy Spirit. Without the Holy Spirit there is no synodality.”1 Even before becoming pope, he emphasized the metaphor of the Holy Spirit at work in a symphony and suggested that the harmonizing (but not homogenizing) of difference would be the mark of the Spirit in this new ecclesial mode of discernment. More recently, synod participants and even Cardinal Mario Grech, secretary general of the Synod of Bishops, have symbolized openness to the Spirit by maintaining an empty chair at synodal gatherings.2 The Spirit lends harmony to differences that are often discordant, if not in opposition to one another. The Spirit [End Page 271] connects these diverse viewpoints because the Spirit is connection itself. The Trinitarian revelation of the Spirit is thus equally relevant: “Without the Holy Spirit who is the bond of both, one cannot understand the connecting unity between the Father and the Son.”3 The Holy Father makes the same point about the reliance of the synod itself on the unifying work of the Spirit: May this Synod be a true season of the Spirit! For we need the Spirit, the ever-new breath of God, who sets us free from every form of self-absorption, revives what is moribund, loosens shackles and spreads joy. The Holy Spirit guides us where God wants us to be, not to where our own ideas and personal tastes would lead us. Father Congar once said: “There is no need to create another Church, but to create a different Church” (True and False Reform in the Church). For a “different Church”, a Church open to the newness that God wants to suggest, let us with greater fervour and frequency invoke the Holy Spirit and humbly listen to him, journeying together as he, the source of communion and mission, desires: with docility and courage.4 Listening to the Spirit is what prompts members of the Church, including the bishop of Rome, to chart out a new synodal path. The report on synodality of the International Theological Commission refers to this prompting as “the parrhesia (‘boldness’) of the Spirit.”5 But the work of the Spirit in a synodal Church does not end with the initial impulse to embark on a new path. The Spirit is invoked and needed also in the process of discernment itself and in the culminating stage of the enactment of the fruits of discernment. In short, the Spirit participates in the beginning, middle, and end of the synodal process (and even, pivotally, in [End Page 272] the reiteration of the process). This essay examines the development of this thought in the pontificate of Francis. At the center of this development is an ongoing question concerning the “when” and “how” of the Spirit. Is synodality altogether new? If synodality is not new, why do we need it now? How will we know the difference between genuinely synodal and false reform, particularly given the strife for the global Church that has attended the German Synodal Way? Francis has much to say about the “when” and the “how,” even though most reporting of his call for a synodal Church has not focused on this fact. The kairós of this Spirit is likewise frequently invoked but not always grasped, especially since kairós is a qualitative and not merely a quantitative category.6 The Spirit of a synodal Church unfolds as a breath of God’s Spirit and as a guide for the Church, and the timing and mode of the unfolding must first be laid out on its own terms. In...

Dynamic prediction modelling and equilibrium stability of a fractional discrete biophysical neuron model

Here, we contemplate discrete-time fractional-order neural connectivity using the discrete nabla operator. Taking into account significant advances in the analysis of discrete fractional calculus, as well as the assertion that the complexities of discrete-time neural networks in fractional-order contexts have not yet been adequately reported. Considering a dynamic fast–slow FitzHugh–Rinzel (FHR) framework for elliptic eruptions with a fixed number of features and a consistent power flow to identify such behavioural traits. In an attempt to determine the effect of a biological neuron, the extension of this integer-order framework offers a variety of neurogenesis reactions (frequent spiking, swift diluting, erupting, blended vibrations, etc.). It is still unclear exactly how much the fractional-order complexities may alter the fring attributes of excitatory structures. We investigate how the implosion of the integer-order reaction varies with perturbation, with predictability and bifurcation interpretation dependent on the fractional-order β∈(0,1]. The memory kernel of the fractional-order interactions is responsible for this. Despite the fact that an initial impulse delay is present, the fractional-order FHR framework has a lower fring incidence than the integer-order approximation. We also look at the responses of associated FHR receptors that synchronize at distinctive fractional orders and have weak interfacial expertise. This fractional-order structure can be formed to exhibit a variety of neurocomputational functionalities, thanks to its intriguing transient properties, which strengthen the responsive neurogenesis structures.

Asian American Studies and LGBTQ Studies: Horizons of Intersectional Alliances

Asian American Studies and LGBTQ StudiesHorizons of Intersectional Alliances Martin F. Manalansan IV (bio) This essay is a brief reflection on the rich intersectional history of Asian American Studies and LGBTQ studies through an autoethnographic account. It focuses on the emergence of productive conjunctions between the two fields as framed by my own career trajectory in academia and community activism. I want to note that this is not an ego-boosting attempt to locate myself as an exemplary case, but I will unabashedly admit that I was a fortunate witness to and an avid participant in the provenance of the continuing fruitful alliances between the two fields. I map these historical and theoretical meeting points as products of historical and biographical encounters and conditions. I believe the "state" of the fields should not be considered as a description of a present condition but rather, as critical assessment of a process, a persistent unfolding, and a continuous voyage of several communities of scholars. At the heart of this essay is not just a story or a history but rather a reflection on enduring questions that have propelled this intellectual crossroad. I offer an invitation or provocation to scholars to take risks, and to listen more closely and sensitively to the evolving world and to lives on the ground. The "roots" of this intersectional history of the two fields are a product of sensitive, activist, and community responses to problems on existing social injustices. As I will point out later, there is a danger in the institutionalization and official recognition of the works coming out of these conjoined fields, especially around the initial impulse for such collaborations which was taking responsibility to engage with ever-increasing and continuing crises of racism, homophobia, transphobia, xenophobia, and extreme economic disparities. At [End Page 11] the end, I briefly gesture to the problems of institutionalization and suggest kernels of a possible future. STREET KNOWLEDGE When I was in graduate school studying for a doctoral degree in anthropology, I was trained as a Southeast Asian Studies scholar. Like many fields in area studies, some countries and cultures were "trendier," more "fundable" or deemed more strategically important than others. My kind dissertation adviser, who conducted fieldwork in the Philippines, very seriously told me that to be a "marketable" Southeast Asian Studies scholar in anthropology (a region already disparaged for its lack of strategic relevance especially after the Vietnam war) that I should focus on Indonesia since it was the treasure trove of anthropological curiosities. The turning point that marked my shift from traditional anthropological area studies to both Asian American and LGBTQ studies was the major turn in the AIDS pandemic in the late 1980s. By that time, the pandemic started devastating communities of people of color, poor people, drug users, and immigrants. After years of living in a bucolic university town in western New York, the sense of safety and distance from the ongoing epidemic slowly fell apart. By 1986, several of the Filipino gay men I met in New York City were coming down with AIDS, some of whom died within the next two years. It was that moment that spurred me to change my dissertation topic from Islamic education in Sumatra, Indonesia, which was a matrilineal society (where the lineage was traced through mother line)–a classic ethnographic topic if there ever was one. I told my adviser that I wanted to study AIDS among Filipino gay men first in San Francisco, then, due to lack of funding, I chose New York where I already had a network of Asian American, primarily Filipino American, gay men. My adviser was naturally disappointed, but like all generous dissertation advisers, he cautioned me that I would be unemployable and that I was taking a major risk that may damage my professional future. Nevertheless, he allowed me the freedom to explore unchartered intellectual and social landscapes despite the dangers and risks involved. When I arrived in New York City to supposedly start my fieldwork in 1989, I became involved in GAPIMNY (Gay Asian Pacific Islander Men of New York) and I helped found Kambal sa Lusog, a Filipino American gay and lesbian group. To fund my research...

Experimental investigation on high-pressure methane jet characteristic single-hole injector

High-pressure gas direct injection (DI) technology benefits engines with high efficiency and clean emissions, and the gas jet process causes crucial effects especially inside an mm-size space. This study presents an investigation on the high-pressure methane jet characteristics from a single-hole injector by analysing jet performance parameters including jet impact force, gas jet impulse, and jet mass flow rate. The results show that the methane jet exhibited a two-zone behaviour along the jet direction in the spatial dimension induced by high-speed jet flow from the nozzle: zone 1 near the nozzle—the jet impact force and jet impulse increased consistently except for a fluctuation due to shock wave effects induced by the sonic jet and no entrainment occurs, and zone II farther away from the nozzle—the jet impact force and jet impulse became stable when the shock wave effects became weak and the jet impulse was conserved with a linear conservation boundary. The Mach disk height was exactly the turning point of two zones. Moreover, the methane jet parameters, such as the methane jet mass flow rate, jet initial jet impact force, jet impulse, and Reynolds number had a monotonous and linearly increasing correlation with injection pressure.

The temporal dynamics between work stressors and health behaviors.

Applying dynamic equilibrium theory (DET), we examined the temporal dynamics between role overload and three health behaviors (sleep, diet, physical activity). Participants (N = 781) completed five surveys, with 1-month lag between assessments, and the data were analyzed using general cross-lagged panel modeling (GCLM). Results indicated that people had stable health behavior patterns (i.e., there were strong unit effects) that were related to stable role overload patterns (i.e., the chronic role overload and health behavior factors were significantly related). Furthermore, while monthly increases (impulses) in role overload had a negative effect on health behaviors concurrently, health behaviors quickly adapted or regressed back toward previous levels (i.e., there were weak autoregressive and cross-lagged effects after accounting for chronic factors). Impulse response functions were created to show the specific proportion of the initial impulse effect that persisted on each health behavior over time. The results of these response functions indicated that diet and physical activity regressed back to previous levels within 1 month, whereas sleep regressed back to previous levels within 2 months. Collectively, our results suggest that people engage in fairly stable patterns of health behaviors and that these patterns are partly determined by chronic role overload. Our results also suggest that people are generally resilient to temporary changes in role overload, such that the resulting immediate changes in behavior do not persist or become habitual. These results underscore the strength of habits and the resistance to health behavior change, as well as provide support for the use of GCLM for studying DET. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Analysis of innovation and creativity impact on the entrepreneur career development

In contemporary literature, entrepreneurship is increasingly attracting attention by emphasizing new observation angles of innovation and creativity. Creativity is exactly the initial impulse that can encourage entrepreneurs to realize an entrepreneurial venture. Finding niches in the market, noticing needs that others have not, as well as different activities, circumstances or events characterize the uniqueness that represents creativity. Entrepreneurial activity generates sustainable economic growth and a better standard of living through innovation and comparative advantage. The innovativeness of an entrepreneur is reflected through a new focus of seeing things, that is, the courage to try something new and different from the existing one. It is precisely in this segment that we can talk about the career of an entrepreneur, which includes a tendency to take risks, enthusiasm for adopting new ideas, accepting new business methods, and, finally, implementing innovative strategies in the business he is engaged in. In the empirical research that was conducted for this work on 168 entrepreneurs, all from the territory of the Republic of Serbia, the connection between innovation, creativity, and career was analyzed.