A novel method to design tolerance of aero-engine casing by integrating 3-D assembly tolerance with performance instability

Assembly quality of aero-engine casing plays a key role in the whole aero-engine, since it is directly related to the final function and dynamic performance. However, during the design phase, the tolerance analysis is usually conducted independently without any consideration of the effect on the dynamic characteristic. This paper aims to integrate manufacturing precision with dynamic performance instability together. First, the 3-D tolerance model of the aero-engine casing is constructed based on the Jacobian-Torsor theory. The target deviation from the tolerance model is defined as the input variable into the vibratory governing equation. Then, the effect of 3-D assembly deviation on the natural frequency is studied. The corresponding frequency distributions for different vibration modes are illustrated. Finally, the mapping relationship between assembly tolerance and fluctuation ratio of natural frequency is established through the 3-D fitted surface. Under the given constraint of performance stability, the optimized tolerance zone is obtained. This work provides a significant guidance for performance improvement and tolerance design in the aero-engine casing assembly.

Mathematical modelling of thermoelasticity problems for thin biperiodic cylindrical shells

The objects of consideration are thin linearly thermoelastic Kirchhoff-Love-type circular cylindrical shells having a periodically microheterogeneous structure in circumferential and axial directions (biperiodic shells). The aim of this contribution is to formulate and discuss two new averaged mathematical models for the analysis of selected dynamic thermoelasticity problems for the shells under consideration: the non-asymptotictolerance and the consistent asymptotic models. The starting equations are the well-known governing equations of linear Kirchhoff-Love theory of thin elastic cylindrical shells combined with Duhamel–Neumann thermoelastic constitutive relations and coupled with the known linearized Fourier heat conduction equation in which the heat sources are neglected. For the microperiodic shells under consideration, the starting equations mentioned above have highly oscillating, non-continuous and periodic coefficients. The tolerance model is derived applying the tolerance averaging technique and a certain extension of the known stationary action principle. It has constant coefficients depending also on a cell size. Hence, this model makes it possible to study the effect of a microstructure size on the global shell thermoelasticity (the length-scale effect). The consistent asymptotic model is obtained using the consistent asymptotic approach. It has constant coefficients being independent of the period lengths. Moreover, the comparison between the tolerance model for biperiodic shells proposed here and the known tolerance model for cylindrical shells with a periodic structure in the circumferential direction only (uniperiodic shells) is presented.

The Transcription Factor FRA-1/AP-1 Controls Lipocalin-2 Expression and Inflammation in Sepsis Model

Sepsis is a life-threatening condition characterized by excessive inflammation in its early phase. This is followed by an aberrant resolution phase associated to a prolonged period of immune suppression that can ultimately lead to multiple organ dysfunctions. This immunosuppression can be mediated by the functional reprogramming of gene transcription in monocytes/macrophages in response to prolonged lipopolysaccharide (LPS) exposure. Surprisingly, there is no report on the role of AP-1 transcription factors in this reprogramming process. Herein, we used the endotoxin tolerance model on murine bone marrow-derived macrophages in which tolerant cells stimulated twice with LPS were compared to naïve cells stimulated once. Out of all AP-1 transcription factors tested, Fosl1 gene stood out because of its unique regulation in tolerized cells. Moreover, we could correlate FRA-1 expression to the expression of an essential anti-inflammatory molecule involved in sepsis response, Lipocalin 2 aka NGAL. Identical results were obtained in human PBMC following the endotoxin tolerance model. When using FRA-1 deficient macrophages, we could confirm that FRA-1 regulates NGAL expression during the tolerant state. Interestingly, ChIP-seq and ChIP-qPCR revealed the binding of FRA-1 on Lcn2 promoter after LPS stimulation in these cells. Finally, we used an in vivo septic model of consecutive injection of LPS, in which the second stimulation is performed before the resolution of inflammation, in wild type and FRA-1 deficient mice. NGAL secretion was elevated in lung, spleen and serum of wild type tolerant mice, whereas it was significantly lower in tolerant FRA-1 deficient mice. Moreover, an increased inflammatory state likely dependent of the low level of NGAL was observed in these FRA-1 deficient mice. This was characterized by an increase of neutrophil infiltration in lung and an increase of apoptotic follicular cells in spleen. This suggests that FRA-1 expression supports resolution of inflammation in this model. Collectively, our data indicate that FRA-1 is involved in myeloid cell tolerance responses by mediating the functional reprogramming of Lcn2 transcription in response to prolonged LPS exposure. In conclusion, FRA-1 may have a protective role in the tolerance response of sepsis through the regulation of NGAL, leading to resolution of inflammation.

A Markov-Based Intrusion Tolerance Finite Automaton

It is inevitable for networks to be invaded during operation. The intrusion tolerance technology comes into being to enable invaded networks to provide the necessary network services. This paper introduces an automatic learning mechanism of the intrusion tolerance system to update network security strategy, and derives an intrusion tolerance finite automaton model from an existing intrusion tolerance model. The proposed model was quantified by the Markov theory to compute the stable probability of each state. The calculated stable probabilities provide the theoretical guidance and basis for administrators to better safeguard network security. Verification results show that it is feasible, effective, and convenient to integrate the Markov model to the intrusion tolerance finite automaton.

Tolerance in A Plural Society: Revealing The Humility of The Sampetan Village Community

<p>The diversity of race, religion, ethnicity, art and culture in a nation is a potential for intolerance in the form of conflicts with nuances of diversity. In fact, diversity creates the value of local wisdom in the sense of diversity. The motto puts tolerance in a strategic domain. Incomplete understanding of religion and radical attitudes that are developing globally make tolerance difficult to materialize. Various studies on the development of a tolerance model have been carried out, but this model is only based on religious, educational, and cultural perspectives. Philosopische grondslag in this study is used to expose community harmony to solve problems of intolerance and radicalism. This study used a qualitative approach, beginning with collecting information from literature studies, collecting data using observation techniques, interviews, as well as documentation, reduction, presentation, and drawing conclusions or data verification. The objectives of this study are (a) to examine the praxis of tolerance based on the philosopische grondslag that has been applied in society, (b) to develop a tolerance model to prevent intolerance and religious deradicalization based on practice to increase peace in society. The results of the study found the values of the Pancasila philosopische grondslag as a habit adopted by a pluralistic society. The case study of the implementation of philosopische grondslag in Sampetan village Boyolali is manifested in the spirit of tolerance and working together to avoid anarchism and radicalism. All of these aspects are the basis for increasing order in society in general.</p>

MODEL TOLERANSI PROPHETIK DI MADINAH PASCA HIJRAH DAN RELEVANSINYA TERHADAP PLURALITAS SOSIAL BUDAYA INDONESIA

Tolerance between religious communities is an important issue to be discussed. This is because in recent years various acts of radicalism and tolerance in the name of religion have increasingly occurred in various parts of the world. This study aims to analyze the inter-religious tolerance model practiced by the Prophet Muhammad in Medina. Using a qualitative method with a literature review approach, this research found that the tolerance built by the Prophet in Medina was dominant with the positive-active tolerance model. This study also found that the reality of tolerance in Medina is basically relevant to the plurality of religions in Indonesia. Therefore, the tolerance model developed by the Prophet in Medina is relevant to be implemented in Indonesia. Of course, the implementation of the tolerance model is by adjusting the sociocultural construction of today's society.