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The effects of anisotropy and radiation cannot be considered negligible while investigating the stability of the fluid in convection. Hence, the purpose of this paper is to analyze how these effects could affect the system while considering a couple-stress dielectric fluid. Therefore, the study establishes the effect of thermal radiation in a couple-stress dielectric fluid with an anisotropic porous medium using Goody's approach (Goody, 1956).

To analyze the effect of radiation on the onset of convection, the Milne–Eddington approximation is employed to convert radiative heat flux to thermal heat flux. The equations are further developed to approximate for transparent and opaque medium. Stability of the quiescent state within the framework of linear theory is performed. The principle of exchange of stabilities is shown to be valid by means of single-term Galerkin method. Large values of conduction–radiation and absorptivity parameters are avoided as fluid is considered as liquid rather than gas.

The radiative heat transfer effect on a couple-stress dielectric fluid saturated anisotropic porous medium is examined in terms of Milne–Eddington approximation. The effect of couple-stress, dielectric, anisotropy and radiation parameters are analyzed graphically for both transparent and opaque medium. It is observed that the conduction–radiation parameter stabilizes the system; in addition, the critical Darcy–Rayleigh number also shows a stabilizing effect in the absence of couple-stress, dielectric and anisotropy parameters, for both transparent and opaque medium. Furthermore, the absorptivity parameter stabilizes the system in the transparent medium, whereas it exhibits a dual effect in the case of an opaque medium. It was also found that an increase in thermal and mechanical anisotropy parameters shows an increase in the cell size, whereas the increase in Darcy–Roberts number and conduction–radiation parameter decreases the cell size. The validity of principle of exchange of stability is performed and concluded that marginal stability is the preferred mode than oscillatory.

The effects of anisotropy and radiation on Rayleigh–Bénard convection by considering a couple-stress dielectric fluid has been analyzed for the first time.

Stakeholders' uncertainty about firms' value drives their urge to get information, as well as managerial disclosure choices. In this study, the authors examine whether and how an important source of uncertainty – the recent COVID-19 pandemic's effect on corporate social responsibility (CSR) disclosure – is beyond managerial and stakeholders' control.

The authors develop a novel construct for daily CSR disclosure by employing computer-aided text analysis (CATA) on the press releases issued by 125 New Zealand Stock Exchange (NZX) listed from 28 February 2020 to 31 December 2020. To capture COVID-19 intensity, the authors use the growth rate of the population-adjusted cumulative sum of confirmed cases in New Zealand on a specific day. To examine the association between the COVID-19 outbreak and companies' CSR disclosure, the authors employed ordinary least squares (OLS) regression by clustering standard error at the firm level.

The authors find a one standard deviation increase in the COVID-19 outbreak leads to a 28% increase in such disclosures. These results remained robust to a series of sensitivity tests and continue to hold after accounting for potential endogeneity concerns. In the channel analysis, the study demonstrates that the positive relationship between COVID-19 and CSR disclosure is more pronounced in the presence of a well-structured board (i.e. a large, more independent board and with a higher proportion of women on it). In further analysis, the authors find the documented relationship varies over the pandemic's life cycle and is moderated by government stringency response, peer CSR pressure and media coverage.

This paper is the first study that contributes to the scant literature examining the impact of the COVID-19 outbreak on CSR disclosure. Prior research either investigates the relationship of the CSR-stock return during the COVID-19 market crisis or examines the relationship between corporate characteristics including the quality of financial information and the reactions of stock returns during COVID-19. The authors extend such studies by providing empirical evidence that managers respond to COVID-19 by increasing CSR disclosure.

I now pass on to an aspect of calcium metabolism which is more topical, but probably more controversial. I refer to the incidence of calcium deficiency. By what means can we determine if people are getting enough, too much, or too little calcium? It is the last condition which concerns us. There are four standard methods. Each have their advantages and their disadvantages. They are (i) a clinical examination; (ii) a dietary survey; (iii) a radiographic examination of the skeleton ; (iv) A study of the calcium balance. (i) The clinical examination is the simplest, but it is the least sensitive method for determining either the early or the mild stages of calcium deficiency. The clinical signs are a softening and bending of the bones (osteomalacia), brittle bones liable to fracture, and tetany. These, however, are signs of late or advanced calcium deficiency, and failure to detect them does not imply that the subject is having enough calcium. Nevertheless, in this country osteomalacia and tetany due to a poor calcium intake have been reported. (ii) A dietary survey is the second method. Before the war several surveys were made, in this country and in America. From their findings there was agreement among reliable authorities that calcium deficiency was present in large sections of the population. Orr has divided the population of this country into six groups according to income. The three lower groups with a total population of over 22,000,000, he found, were getting insufficient calcium. It was shown first, that the consumption of the low calcium foods such as bread and potatoes was practically uniform throughout the classes, and secondly, that the consumption of the calcium‐rich foods, milk, eggs, cheese, green vegetables was low in the poorer classes and rose with income. As income increased the following improvements occurred—disease decreased; children grew more quickly; adult stature was greater; general health and physique improved. It may be argued, that the improvement in health in the higher income groups was due not to better food, but to better housing. This is not so. For, if people in the lower income groups are only given better food, their health approaches that of the higher income groups. Then there are the observations of Dr. McGonigle at Stockton‐on‐Tees. A slum clearance resulted in the removal of poor people to better houses and improved living conditions. The sickness rate increased. Why? Because the higher rents of the new houses prevented these people spending as much money on food as they did when they lived in the slums. Dietary surveys before the war, therefore, support the belief that many people in this country were getting too little calcium. As most of our staple foods have a low calcium content, it follows that the absence of hunger does not necessarily mean the absence of calcium deficiency. (iii) Radiographic examination of the skeleton is the third method. Unfortunately X‐rays of the bone density of the trabeculæ do not readily give an indication of its calcium content unless the decalcification is severe. If we may judge by thyrotoxicosis, where there is an increased loss of calcium from the body, X‐rays show the decalcification only in the most severe 25 per cent. of cases. Radiographic studies will detect however an excessive withdrawal of calcium from the skeleton, before such clinical signs as softening of bones, brittle bones, and tetany develop. In this country there is radiographic evidence of decalcification resulting from low calcium intakes. (iv) Finally there are the observations on the calcium balance. Earlier in this paper it was stated that a normal healthy person requires to ingest 0·55 gram of calcium daily to avoid persistently losing calcium from his skeleton. A daily dose of 0·55 gram calcium then produces calcium equilibrium, and intake equals output. It has also been stated that a daily intake of 0·8 gram is the minimum amount of calcium which will bring about the maximum storage. In other words no matter how much in excess of 0·8 gram calcium daily a healthy adult ingests, he will not store any more calcium than he would if he were taking 0·8 gram. These facts provide us with two means of determining whether calcium deficiency is present or not. Calcium deficiency is present if the figure for calcium equilibrium falls significantly below 0·55 gram daily. Calcium deficiency is present if more storage of calcium takes place with intakes above 0·8 gram daily, than at 0·8 gram daily. Is there any evidence from calcium balance studies in this country that calcium deficiency exists? There is evidence. I have just described the methods which are available for determining whether calcium deficiency is present or not. I believe, on the evidence obtained from all four methods, that, before the war, a large proportion of people in this country were taking too little calcium. I would like at this point to digress for a moment. There are certain people who would have us believe that clinical and radiographic evidence is essential to prove the presence of calcium deficiency. As I have explained, these methods only showed the advanced stages. I reply: “ Must we wait for secondary deposits in the liver, extreme emaciation, ascites, before diagnosing cancer ?”

The purpose of this study is to identify the prescribed formative elements of supply chain resilience (SCR) in literature, to compare them with the unique characteristics of high reliability organisations (HROs) and derive lessons useful for improving SCR.

Two systematic literature reviews are carried out as follows: one on SCR and the other on HRO, which identified 107 studies and 18 papers, respectively. The results from the review are presented, analysed and synthesised.

Findings suggest that despite significant similarities in some of the proposed formative elements for SCR and the characteristics of HROs, the strong managerial commitment exhibited in HROs is absent in SCR literature. More importantly, the most cited characteristic of HROs, which is their flexible decision making structure is pointed out as a prima lesson towards developing resilience in supply chains.

A decision making framework to facilitate flexible decision making for supply chains during crisis is presented. Further, practical lessons are pointed out from principles common to both streams of literature such as redundancy, human resource management, collaboration, agility, flexibility, culture and risk avoidance that can be implemented in supply chains.

This paper is the first study to systematically review HROs, adapt a HRO decision making framework and also apply the Cynefin framework to SCR. This, therefore, provides the basis to launch further research into the use of these theories and the role of decision-making in SCR creation.

Recognizing the severity of COVID-19 on the US economy, the authors investigate the behavior of US-listed firms towards leverage speed of adjustment (SOA) during the pandemic. While prior evidence (based on an international study) shows that firm leverage increased during the pandemic leading to a higher SOA toward leverage ratios, leverage for US firms during the same period reduced drastically. Yet there is a dearth of empirical studies on the behavior of US-listed firms' SOA during the pandemic. The authors fill this void.

The study includes US-listed non-financial and non-utility firms for the period 2015Q1-2021Q4, covering a total sample of 45,213 firm-quarter observations. The authors’ empirical strategy is based on the generalized method of moments (GMM) and firm-fixed effect methodology, controlling for firm- and quarter-fixed effects.

Three main findings are established: (1) while the SOA toward book target increased during the pandemic, SOA toward market target increased significantly only for less valued and cash-constrained firms; (2) firms in states most impacted by the pandemic adjusted faster towards target ratio; and (3) while the emergence of the pandemic and the overall firm-level risk increased (decreased) the deviation from book (market) target, firm-level risk partially mediated the effect of the pandemic on how far firms deviated from target ratio.

This study enhances our understanding of leverage adjustment during the crisis and shows that risk avoidance motive and the market value of firms are key determinants of convergence rate during the crisis and further demonstrates that market leverage is more sensitive to market dynamics. As such, caution must be taken when dealing with and interpreting market leverage SOA.

Although prior evidence based on international study provides insights into how firms behave toward their leverage ratios because of the pandemic, little is known about how US firms react to the pandemic in terms of the target ratios, particularly (1) since the USA is one of the severely affected countries and (2) firms in the USA reduced their leverage ratios as against what prior evidence shows. The authors provide evidence to explain how and why US firms reacted toward their SOA during the pandemic.

Recent lapses in the management of high hazard organizations, such as the Fukushima event or the Deepwater Horizon blast, add considerable urgency to better understand the complicated and complex phenomena of leading and managing high reliability organizations (HRO). The purpose of this paper is to offer both theoretical and practical insight to further strengthen reliability in high hazard organizations.

Phenomenological study based on over three years of research and thousands of hours of study in HROs conducted through a scholar-practitioner partnership.

The findings indicate that the identification and the management of competing tensions arising from misalignment within and between public policy, organizational strategy, communication, decision-making, organizational learning, and leadership is the critical factor in explaining improved reliability and safety of HROs.

Stops short of full-blown grounded theory. Steps were made to ensure validity; however, generalizability may be limited due to sample.

Provides insight into reliably operating organizations that are crucial to society where errors would cause significant damage or loss.

Extends high reliability research by investigating more fully the competing tensions present in these complex, societally crucial organizations.

Ultrasound is simply a name given to sound waves whose frequency (pitch) is too high to be detected by the human ear. The use of low‐intensity ultrasonic waves in level measurement, flow detection, and medical imaging is well known. Here, a pulse of ultrasound is used to ‘probe’ the sample under investigation; comparison of the pulse shape before and after transmission, and a measurement of the transit time in the sample can provide information on many physical parameters. For these applications, the intensity of the ultrasonic burst is not sufficient to affect the material, and no chemical or physical changes are involved.

The case for physical activity has been established through its impact on reduction in the risk of physical ill‐health such as coronary heart disease. However, there is increasing interest in its potential for a) treating and preventing mental illness and also b) the promotion of mental well‐being in the general public. The topic is now widely studied with over 30 published narrative or meta‐analytic reviews of research into the effect of exercise on constructs such as clinical or subclinical depression or anxiety, self‐esteem, affect and mood, resilience to stress, cognitive function or sleep. This paper provides a summary and appraisal of the evidence for the effect of exercise on mental health and addresses key issues that face the use of exercise as a medium for health promotion.

The purpose of this paper is to establish a criterion for the global asymptotic stability of fixed-point state–space digital filters using saturation overflow arithmetic.

The method of stability analysis used in this paper is the second method of Lyapunov. The approach in this paper makes use of a precise upper bound of the state vector of the system and a novel passivity property associated with the saturation nonlinearities.

The presented criterion leads to an enhanced stability region in the parameter-space as compared to several existing criteria.

When dealing with the design of fixed-point state–space digital filters, it is desirable to have a criterion for selecting the filter coefficients so that the designed filter becomes free of overflow oscillations. The criterion presented in this paper provides enhanced saturation overflow stability region and therefore facilitates the designer greater flexibility in selecting filter parameters for overflow oscillation-free realization of digital filters.

The approach uses the structural properties of the saturation nonlinearities in a greater detail. The exploitation of upper bound of the system state vector together with a new passivity property of saturation nonlinearities is a unique feature of the present approach. The presented approach may lead to results not covered by several existing approaches.

Concrete-filled double skin tube (CFDST) columns are considered one of the most effective steel-concrete composite sections owing to the higher load carrying capacity as compared to its counterpart concrete-filled tube (CFT) columns. This paper aims to numerically investigate the performance of axially loaded, circular CFDST short columns, with the innovative strengthening technique of providing stiffeners in outer tubes. Circular steel hollow sections have been adopted for inner as well as outer tubes, while varying the length of rectangular steel stiffeners, fixed inside the outer tubes only, to check the effect of stiffeners in partially and full-length stiffened CFDST columns.

The behaviour of these CFDST columns is investigated numerically by using a verified finite element analysis (FEA) model from the ABAQUS. The behaviour of 20-unstiffened, 80-partially stiffened and 20-full-length stiffened CFDST columns is studied, while varying the strength of steel (f_yo = 250–750 MPa) and concrete (30–90 MPa).

The FEA results are verified by comparing them with the previous test results. FEA study has exhibited that, there is a 7%–25% and 39%–49% increase in peak-loads in partially stiffened and full-length stiffened CFDST columns, respectively, compared to unstiffened CFDST columns.

Enhanced strength has been observed in partially stiffened and full-length stiffened CFDST columns as compared to unstiffened CFDST columns. Also, a significant effect of strength of concrete has not been observed as compared to the strength of steel.