Partial Collapse Research Articles

Site Specific Hazard Assessment and Multi-Level Seismic Performance Evaluation of Historical Mosque

ABSTRACT This study highlights the continued need for numerical simulation methods to predict the earthquake response and damage of masonry mosques, despite recent advances in research. The Kamanlı Masonry Mosque in İzmir, Turkey was selected as a case study for this purpose. A probabilistic seismic hazard analysis was conducted using a uniform Poisson process model with 50-year probabilities of 2%, 10%, and 50%. Earthquakes from seismic sources were excluded based on time and distance, and the annual recurrence relationships of the source areas were determined using the least squares method. The non-linear response of a masonry mosque was investigated using the discrete element approach to study the impact of site conditions on its structural performance. Nonlinear dynamic analyses were conducted using records representing seismic events with 475- and 72-year return periods. The results indicated that the mosque is highly vulnerable to earthquakes, as the 475-year records resulted in significant damage and partial collapse. Damage indicators were employed to assess the response to the 72-year records, highlighting the most vulnerable areas that should be prioritized in any restoration efforts.

Correlated insulator collapse due to quantum avalanche via in-gap ladder states

The significant discrepancy observed between the predicted and experimental switching fields in correlated insulators under a DC electric field far-from-equilibrium necessitates a reevaluation of current microscopic understanding. Here we show that an electron avalanche can occur in the bulk limit of such insulators at arbitrarily small electric field by introducing a generic model of electrons coupled to an inelastic medium of phonons. The quantum avalanche arises by the generation of a ladder of in-gap states, created by a multi-phonon emission process. Hot-phonons in the avalanche trigger a premature and partial collapse of the correlated gap. The phonon spectrum dictates the existence of two-stage versus single-stage switching events which we associate with charge-density-wave and Mott resistive phase transitions, respectively. The behavior of electron and phonon temperatures, as well as the temperature dependence of the threshold fields, demonstrates how a crossover between the thermal and quantum switching scenarios emerges within a unified framework of the quantum avalanche.

Reimagining Probation Practice: Re-forming Rehabilitation in an Age of Penal Excess. By BurkeL.,CarrN., CluleyE., CollettS. and McNeillF. (eds) (Routledge, 2022, 247pp. £34.99 pbk)

Twenty authors have contributed to this collection of 13 essays. They are drawn from every branch of the ‘probation’ community—practitioners, inspectors, academic analysts and teachers. So, unsurprisingly, the quality of the expositions varies a good deal and, somewhat surprisingly, one voice is almost completely absent: that of offenders. Apart from a short quote from a bemused participant in a group work programme—a participant who clearly cannot see how he’s going to escape the traps surrounding him (p. 59)—the offender voice is absent. A bit of ‘lived experience’ would have leavened this sometimes ritualistically worthy loaf. The core message, around which all the contributors have mustered, is a plea, clearly set out in the editors’ introductory manifesto, that probation practitioners strive to retain and develop a commitment to the serious ambition of encouraging offender desistance. This objective is easier said than done given the context within which probation services are now delivered. Indeed, a mood of scarcely concealed desperation occasionally surfaces in the editors’ account. For the backcloth to probation work, be it the preparation of court reports, the supervision of community orders, the delivery of offender programmes or the resettlement of prisoners, is a scarred landscape of: gross and worsening social and economic inequality; increasing and deepening poverty; a housing rental market geared to ownership and inheritance of wealth rather than public utility; employment practices increasingly characterized by zero hour contracts and insecurity of tenure; and the partial collapse of major national and local authority public services whose remit includes the redress of the multiple trauma—childhood, familial, medical and military—which lies behind most serious offending.

Numerical analysis of suspension bridges with box girders subjected to detonations

This paper focuses on the dynamic behavior of a typical three-span suspension bridge subjected to blast loads. Three-dimensional finite element models were established to simulate the blasting excavation of these structures using the explicit dynamic analysis code LS-DYNA. The explosive charge model was developed using the *LOAD_BLAST_ENHANCED tool in the LS-DYNA software. The accuracy of finite element models was validated against existing experimental and numerical results. The failure patterns and damage process of the bridge under explosive loading on the deck were analyzed, while the effects of mass and location of explosive charge were further explored. Dynamic responses such as displacement, stress, and strain were discussed and compared. Based on the computed results, the most critical location of the explosives was assessed. The results indicated the superior performance of the bridge against near-tower detonation over mid-span detonation. The deck exhibited disproportionate collapse due to very high charges of 5000 kg and 8000 kg TNT detonation at mid-span. The blast outcome generated on the bridge's components due to high charges from 1000 kg TNT to 2500 kg TNT at a standoff distance of 2 m was identified as partial collapse. Moderate charges of 250 kg TNT and 500 kg TNT at standoff distances of 2 m and 3 m led to plastic deformation without fracture of the bridge's component. Very high TNT charges at near-tower detonation caused only partial collapse. The severity of cable relaxation and detachment from the deck due to mid-span detonation exceeded the near-tower one.

Hot Brownian Motion of Thermoresponsive Microgels in Optical Tweezers Shows Discontinuous Volume Phase Transition and Bistability.

Microgels are soft microparticles that often exhibit thermoresponsiveness and feature a transformation at a critical temperature, referred to as the volume phase transition temperature. Whether this transformation occurs as a smooth or as a discontinuous one is still a matter of debate. This question can be addressed by studying individual microgels trapped in optical tweezers. For this aim, composite particles are obtained by decorating Poly-N-isopropylacrylamide (pNIPAM) microgels with iron oxide nanocubes. These composites become self-heating when illuminated by the infrared trapping laser, performing hot Brownian motion within the trap. Above a certain laser power, a single decorated microgel features a volume phase transition that is discontinuous, while the usual continuous sigmoidal-like dependence is recovered after averaging over different microgels. The collective sigmoidal behavior enables the application of a power-to-temperature calibration and provides the effective drag coefficient of the self-heating microgels, thus establishing these composite particles as potential micro-thermometers and micro-heaters. Moreover, the self-heating microgels also exhibit an unexpected and intriguing bistability behavior above the critical temperature, probably due to partial collapses of the microgel. These results set the stage for further studies and the development of applications based on the hot Brownian motion of soft particles.

Neurobiological Staging with Special Reference to Sleep Apnoea Syndrome: An Update

Abstract: Sleep apnea (SA) or Obstructive sleep apnoea (OSA) is a widely spread sleep disorder marked by repetitions of a complete or partial collapse of the upper airways during sleep. The pathogenesis of OSA is due to the recurrent obstruction of the pharyngeal airway during sleep. The risk factors contributing to upper airway obstruction are obesity, cardiovascular diseases, craniofacial changes, alcohol and smoking. The condition is associated with significant morbidity and mortality. The diagnosis is established with polysomnography (PSG). Lifestyle changes such as weight loss, keeping away from alcohol, tobacco, and sedatives and altering the usual sleeping body position help out in decreasing apnoea symptoms. Various treatments are available for the successful management of this disease, such as continuous positive airway pressure (CPAP) is mainly used in patients with severe SA and oral appliances are widely used in mild to moderate SA and for patients intolerant to CPAP therapy. There are many options available for surgical therapy, with the UPPP (Uvulopalato-pharyngoplasty) being the most widely employed. Also, a number of medications such as tricyclic antidepressants (TCA’s), decongestants, nasal steroids, antihypertensive agents, CNS stimulants and supplementary oxygen are used for treating patients with OSA.

Response of reinforced concrete structural members exposed to high temperature fire and retrofitting of fire damaged structural members adopting R.C jacketing

When fire breaks out in a building, the most important criteria is the retention of stability of the fire damaged structure against partial or total collapse. An actual case study has been presented in the current work on the response of structural elements present in a 12 storey RC multi storied building exposed to high temperature during a fire event taken place in it. The rise of the temperature in the structural elements in the event of a fire exposure, causes physio-chemical changes in the materials the structural members are made up of, namely, concrete and reinforcing steel, leading towards the degradation of material stiffness, elastic modulus and decrease in the load carrying capacity of such structural members. In the present work, two compartments at the periphery of the building are exposed to high temperatures of 300 °C, 500 °C and 700 °C, and the structural analysis is carried out with dead load, live load and temperature. Structural response of the structural members is assessed, as well as maximum displacements, internal forces developed in them as a consequence of exposure to high temperature has been recorded. As per observation, a combination of temperature and gravity loads(DL&LL), increases the probability of the structure to undergo a higher degree of damage, as the restrained structural members due to the effect of temperature, undergo nonlinear deformations (buckling of columns and bowing action of beams). Reinforced concrete columns and beams that might have undergone a repairable degree of damage due to different temperatures have been retrofitted adopting the RC jacketing method. It is observed from the results of the present case study that, by adopting RC jacketing to retrofit temperature damaged structural members, present in the structure, an enhancement in the stiffness and overall stability of the structure is observed to further withstand externally applied loads.

Pushover Analysis of Multi-Story Reinforced Concrete Frame Structure

Pushover analysis is a non-linear static procedure (NSP) used to examine the structural response of a building during the inelastic limit before it reaches the edge of partial or total collapse. In this study a model of multi-story reinforced concrete building along with applied loads is analyzed in powerful non-linear static procedure using computer software ETABS. A limited number of horizontal forces are then applied to imitate the impact of ground movement. The building is supposed as a 6-story building, no shear walls used in the model as the level of earthquake hazard assumed very low. Moreover, deformations are determined. The forces would then be increased gradually, NSPs convert multi-degree of freedom models to single-degree of freedom models utilizing a pushover analysis to determine capacity curve or pushover curve which is horizontal roof displacement vs base shear, This curve plot reveals the highest base motion that the structure can withstand, and then estimate the maximum global displacement by combining a ground response spectrum with the capacity curve.

Scenario-based probabilistic hazard assessment for explosive events at the San Salvador volcanic complex, El Salvador

We present a scenario-based, probabilistic hazard assessment for the San Salvador volcanic complex (SSVC), a volcanic field located in the vicinity of San Salvador that includes the El Boquerón stratovolcano and 25 monogenetic vents. We define a set of likely eruption scenarios for tephra fallout and pyroclastic density currents (PDCs). The eruption scenarios range from violent Strombolian eruptions with a significant uncertainty in source position to sub-Plinian and Plinian activity fed from the central cone. The adopted methodology is mainly based on numerical modeling using Tephra2 (adopting the software TephraProb) to study tephra fallout and the branching box model and the branching energy cone model (adopting the programs BoxMapProb 2.0 and ECMapProb 2.0) to describe inertial and frictional PDCs, respectively. Despite the dominant W-WSW-trending winds, numerical results show that Plinian eruptions at El Boquerón volcano are able to deposit thick tephra layers in the metropolitan area of San Salvador city, likely reaching mass loads of the order of 100 kg/m2 (conditional probability of 50%). The simulated sub-Plinian events highlight the seasonal influence of wind patterns. In fact, the conditional probability of significant tephra sedimentation in San Salvador city is strongly reduced when eruptions occur during the rainy season. Numerical modeling of violent Strombolian eruptions is performed considering uncertainty in vent position. Results show that the conditional probability of depositing tephra mass loads higher than 10 kg/m2 at a given point reaches a maximum value of ∼7% on the NW flank of the volcano, at about 8 km from the central crater. On the other hand, very low conditional probabilities (<1%) are obtained for San Salvador city for any relevant threshold (10 kg/m2 or more) of tephra mass load during violent Strombolian events. Regarding PDCs, results show that those produced during large-scale Plinian eruptions are able to invade significant areas of the volcano surroundings, including San Salvador city. PDCs generated from the partial collapse of a sub-Plinian eruption column exhibit maximum inundation probabilities on the N, W and S flanks of the volcano. Cerro El Picacho exerts a significant shield effect on the propagation of these PDCs, with low inundation probabilities for San Salvador city (<3%). Finally, coupling published vent opening probability maps and numerical modeling of small-scale PDCs yields maximum inundation probabilities on the NW flank of the volcano, reaching maximum conditional probabilities of the order of ∼10% and values of about 5% near the village of Nuevo Sitio del Niño.

Partial talar replacement with a novel 3D printed prosthesis

Background The treatment of talus avascular necrosis (AVN) is challenging owing to its unique anatomical features. Despite decades of studies, till date, there is no appropriate treatment for talus AVN. Therefore, surgeons need to develop newer surgical methods. In the present study we introduce a new surgical method, 3D printed partial talus replacement (PTR), to treat partial talus necrosis and collapse (TNC). Methods A male patient with talus AVN underwent PTR in our hospital. The morphology of the talus was quantified using 3D computed tomography (CT) imaging. A novel 3D printed titanium prothesis was designed and manufactured according to the findings of the CT imaging. The prosthesis was applied during talus replantation surgery to reconstruct the anatomical structure of the ankle. The follow-up period for this patient was 24 months. The visual analog scale (VAS) scores before and after surgery, American Orthopedic Foot and Ankle Score (AOFAS), ankle range of motion, and postoperative complications were recorded to evaluate the prognosis. Results The anatomical structure of the talus was reconstructed. The patient was satisfied with the effects of treatment, recovery, and function. The VAS score decreased from 5 to 1. The AOFAS improved from 70 to 93. The range of motion remained the same as that during the pre-operation. The patient returned to a normal life. Conclusion 3D printed PTR is a new surgical method for talus AVN that can provide satisfactory outcomes. In future, PTR might be an effective and preferential treatment for the treatment of partial talus AVN and collapse.

Failures and damages of historical masonry structures induced by 2012 northern and 2016–17 central Italy seismic sequences: Critical issues and new perspectives towards seismic prevention

The work analyses some observed structural criticalities in historical masonry structures emphasized by the seismic events of May 2012, in Emilia, and of August-October 2016, in Central Italy. The causes that brought to different damage scenarios in the historic centres and to the different degree of damage evolution of the buildings, have been investigated, comparing their construction and dynamic features, such as the natural vibration periods of the different construction typologies with the spectral accelerations and the amplification periods distinctive of the seismic events. In particular, starting from the evidence of the damage observed on the built heritage of some of the centres most affected by the two seismic sequences, and from the characteristics of the seismic signals recorded at the considered sites, it is proposed a study which analyses some criticalities, in relation to preventive purposes of the technical standards, specifically with reference to historical constructions. Among the main criticalities highlighted in the present work, it should be noted the remarkable difference between the design spectra and the spectra of the recorded seismic events (real earthquakes), and the circumstance that in reality the constructions generally are interested by more seismic shocks (multi-events) characterized by higher intensities with respect to the ones expected by the building code. Such feature gives rise to a criticality for the operators acting in the emergency phases of rescue and temporary securing, who find themselves operating in high hazardous conditions, due to the high vulnerability of already damaged built heritage induced by the main-shock, and by the high probability (near certainty) that, in the short period, events having intensities and characteristics similar to the main-shock may occur. Moreover, the evolution of the damages, with progressive crumbling associated to global or partial collapses, due to the sequence of shocks (multi-events), which had interested thousands of buildings in the historical centres (and not only) subjected to the seismic sequence, bare witness of criticalities in the preventive approach proposed at national level. The analysis of the criticalities highlighted in the present work allows to envisage an approach which considers for the structures, historical or not, adequate performance requirements with respect to the emergency, temporary and permanent securing phases, accounting for the multi-event seismic context typical of the Italian territory.

Microwave Modification of Quinoa Grains at Constant and Varying Water Content Modulates Changes in Structural and Physico-Chemical Properties of the Resulting Flours

Microwave-assisted heat moisture treatment (MWT) was applied to quinoa grains, a nutritious gluten-free pseudocereal of great interest in food product development, to achieve the physical modification of the quinoa flour. The effect of treating quinoa grains at different initial water contents (WC; 10%, 20%, and 30%) in two operational systems was compared: one open at atmospheric pressure and variable WC (V system), and the other in hermetic containers at constant WC (C system). The morphological structure of the obtained flours and their techno-functional, rheological, and thermal properties were evaluated. MWT proved to be effective in modifying these properties, the main effects probably being caused by protein denaturation and aggregation, and intragranular molecular rearrangements of starch, with disruption of short-range molecular order and even the partial collapse of starch granules in the samples treated at the highest WC. The greatest differences were observed for the 20 and 30% WC treated-samples, particularly when using C system, which increased their water absorption capacity and decreased their foaming, emulsion, and gel-forming capacities. Based on these results, the control of WC and its evolution during MWT of quinoa grains appears to be a viable and effective approach to adapt flour functionality to the needs of food production, allowing a wider range of flour properties depending on the MWT conditions.

Surface Properties and Microstructures of Al-SBA-15 under Different Temperature Calcinations in Relation to Adsorption Performance

In this study, the calcination temperature was adjusted to influence the properties, including surface alumina types, microstructure, and surface acidity, and then to explore their association with the performance of As(V) adsorption after preparing aluminum-modified SBA-15 (Al-SBA-15x) by the incipient wetness impregnation method. The results showed that calcination promoted the formation of aluminum oxides with different coordination environments on SBA-15 carriers, resulting in different kinds of acid sites and Al–OH groups, which were the adsorption sites for As(V). However, with the increase in the calcination temperature, the total surface acidity on the Al-SBA-15x samples gradually decreased, and the dehydration and dehydroxylation reactions of aluminum oxides occurred, which reduced the Al–OH groups and changed the acid–base environment on the samples. Besides, high-temperature calcination caused a partial collapse of mesoporous channels, which was not conducive to dispersing the active adsorption centers on the surface and further reduced the effective utilization of active adsorption centers. Therefore, the adsorption capacity of an Al-SBA-15x adsorbent for As(V) decreased with the increase of the calcination temperature. Furthermore, kinetic models were used to investigate the relationship between the microstructure and adsorption processes. Finally, recycling tests were performed to demonstrate the reusability of Al-SBA-15x samples.

Carotid Endarterectomy in Patients with Near Occlusion with Full or Partial Collapse

Carotid Endarterectomy in Patients with Near Occlusion with Full or Partial Collapse

RISK ANALYSIS OF RESTORATION WORKS BY FINE KINNEY METHOD: AN EVALUATION OVER MASONRY CIVIL ARCHITECTURE EXAMPLES IN FATIH DISTRICT, ISTANBUL

Restoration interventions aims at conserving heritage structures. Different situations may occur during restoration works comparing to standard construction works. These differences may cause special risks for workers and the structure itself. Risk analysis is widely used in restoration field in the world as a work plan routine. Definite division between restoration and standard works hasn’t been defined in Turkey. Aim of the study is revealing what kind of different risks restoration works carry, creating awareness and making recommendations for avoiding these risks. As method of this study, Fine Kinney Method was chosen. The risk factor was obtained by using probability, severity and frequency values. Listed masonry houses from Fatih district were chosen. The region is composed of civil architectural examples more densely comparing to whole Istanbul. The most important criteria is the fact that these houses are among the oldest masonry examples in Istanbul. They carry more risks with their current deterioration levels. The possible risks were listed and documented. The results were presented using Fine Kinney Method. Falling from height and partial collapse are found as main risks in restoration works. Risk levels and risk types of potential risks in restoration works show differences than the standard construction applications.

STABILIZATION OF AN ANATOMICAL WAX MODEL OF THE COMPLUTENSE VETERINARY MUSEUM WITH THE HELP OF 3D DIGITAL TECHNOLOGIES

"Between the 17th and 20th centuries, polychrome beeswax anatomical models played an important role in the transmission of anatomical knowledge thanks to the high degree of accuracy and realism they were able to achieve in the representation of the most delicate structures of the organism. However, due to the fragility of this material, some of these artefacts now survive in a rather precarious state of conservation. Due to the lack of consistency of some of the internal support structures, some of these figures have been damaged or their integrity has been seriously compromised. In this article we show a case of stabilisation using a polymethylmethacrylate support of a model from the Complutense Veterinary Museum, representing the head of a horse, which has suffered the loss of some parts and shows significant cracks and fractures due to the partial collapse of the internal metal framework. The methodology used was based essentially on the use of digital technologies, to minimise the handling of the work. Based on a virtual copy obtained by 3D scanning, a specific support that fits perfectly to the surface of the figure has been designed. Subsequently, some of the pieces were produced using 3D printing in order to subject them to functional and aesthetic tests and, finally, the support was manufactured using numerical control machining. The result meets the requirements of stability and minimum aesthetic impact."

Rocking Analysis of Towers Subjected to Horizontal Forces

In seismic-prone areas, ecclesiastical masonry complexes have shown very high vulnerability, as detected after the last Italian earthquakes, such as those that occurred in L’Aquila (2009), Emilia-Romagna (2012), Central Italy (2016), and Ischia (2017). Partial collapses often affect these types of aggregate buildings due to the presence of highly vulnerable elements, such as bell towers. Preliminary analyses, including straightforward and quick methods, are necessary to assess their vulnerability. This paper proposes a simplified method to analyse bell tower dynamic behaviour and the results obtained are compared with several different approaches. The first is based on the dynamics of two rigid blocks (bell tower and lower building), and the second concerns a single block (bell tower only). The proposed method can be considered as a quick procedure involving few parameters to provide a preliminary analysis before use of more complex models such as finite element models. It aims to provide a valuable tool for the initial evaluation of the stability and risk index of the structure. The double-block model considers the associations between the rocking of the bell tower and the sliding motion of the underlying building. A parametric evaluation for different friction coefficients is proposed. The results are represented as rotation time histories and compared with analysis of the single vulnerable element, i.e., the bell tower subjected to the floor spectrum. The results show that high excitation frequency and friction coefficient values make the bell tower stable, and that the simplified model provides a clear safety advantage.

Machine learning for the prediction of evaluation of existing reinforced concrete structures performance against earthquakes

Earthquakes are challenging disasters that pose a huge threat to the urbanized world. In particular, the majority of the existing reinforced concrete (RC) building stock in developing countries such as Turkey is under huge seismic risk. These structures are at risk of partial or complete collapse under the effects of strong ground motions, due to some deficiencies in the structures. Therefore, seismic evaluation of existing buildings with a predominantly RC structural system is vital to reduce the potential seismic risk. In this study, machine learning (ML) techniques have been used for the prediction of the existing RC buildings’ performance against earthquake. The k-fold cross-validation has been employed to check the accuracy of the ML techniques. Random Forest (RF) provided the highest performance among the other ML techniques used. Sensitivity analysis have also been performed to determine the most significant factors in the prediction of the performance of the buildings. The results show that the building age, concrete compression strength, maximum column stirrup distance, steel yield strength, and the existence of corrosion have a high impact on the assessment of building performance.

Evaluation of Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio in Obstructive Sleep Apnea Patients

Background: Obstructive sleep apnea (OSA) is a condition marked by recurrent total or partial collapses of the upper airway during sleep, which result in obstructive apneas, hypopneas, and/or respiratory effort-related arousals.

ANALISIS KEANDALAN BANGUNAN GEDUNG (STUDI KASUS: BANGUNAN GEDUNG REKTORAT UNIVERSITAS MAHASARASWATI DENPASAR)

The Building in situations and conditions until now there are still some that have experienced partial or complete collapse due to several causes, namely natural disasters, converted building functions that cause undue pressure / load, or structural failures or errors. In this regard, it is desirable that there will be a reliability check on the building. The building studied in this study is the Rectorate Building of Mahasaraswati University Denpasar. In this case, to evaluate the reliability of the Building, an analysis was carried out with interviews and questionnaires with interview samples, namely 14 speakers and questionnaires, namely 34 respondents. In this study using descriptive research methods with quantitative and qualitative approaches. Factors that affect the reliability of the rectorate building of Mahasaraswati University Denpasar include architecture, structure, utility and fire protection, accessibility, building arrangements and the environment. The results of the evaluation of the level of reliability of this building include architecture, namely 87% which includes less reliable (75 - &lt; 95%), structures which are 96% which include reliable (95 - 100%), utilities and fire protection which are 86% which include unreliable (&lt; 95 %), accessibility which is 82% which includes less reliable (75 - &lt; 95%), and building and environmental arrangements which are 57% which include unreliable (&lt; 75%). The total reliability value is 82% where the building of the Rectorate Building of Mahasaraswati University Denpasar is less reliable (75 - &lt; 95%)