Heat transfer characteristics of locally manufactured hollow concrete blocks

The paper is focused on the investigation of the thermal properties of traditional local building blocks with the aim of understanding its resistance to the transfer of heat. The building blocks under test shall be hollow concrete blocks (HCBs) manufactured by a local company. The hot box method technique shall be applied to obtain values of the thermal conductivity of the respective HCBs being tested. Dimensions and weight of these blocks shall be recorded and compression testing carried out. The correlation between thermal conductivities and compression strength shall provide useful information on the thermo-physical behaviour of these building elements. The first part of this paper reports on the actual setup of the hot box. It is then followed by the description of the testing methodology adopted and calculations applied to obtain values for comparisons between the different HCBs tested. The final part of the paper is then focused on the discussion of results and the ultimate conclusions. The aim is to succeed in obtaining a correlation between U-values of existing local HCBs, their density and compressive strength, which will enable future extrapolation of results, based on simple measurements such as density.Bajada New Energy, General Membrane, EcoGroup, Econetique, Energy Investment, JMV Vibro Blocks, Solar Engineering, Solar Solutionspeer-reviewe

Holocene LSA archaeology from Equus Cave, Buxton-Norlim Limeworks, South Africa : an analysis of the bone tool assemblage

Abstract: Equus Cave, Buxton-Norlim Limeworks, near Taung, North West Province, South Africa, was first excavated between 1978 and 1982. While the site dates to the terminal Pleistocene and Holocene the precise age of the different layers is debated, as is the technological assignment of the deepest deposits, which are said to contain both Later or Middle Stone Age elements. While the faunal assemblage and some of the human remains have been published, the archaeology has never been fully analysed or reported. New excavations in 2012 revealed numerous artefacts including ochre, something not previously noted for this site. Comparison of total lithic artefact counts versus faunal NISPs and MNIs shows that the height of human occupation occurred during the Holocene, with preliminary analysis of the >6000 lithic assemblage indicating a dominance of notched artefacts, which, coupled with the presence of 16 bone points, is characteristic of other HoloceneWilton (Later Stone Age) sites in the region. The focus of this paper is the 16 bone points, which include projectile points and link-shafts, and how these items were manufactured and used. The results provide one of the first detailed descriptions of Later Stone Age bone tools, including rare specimens that are mostly complete or still preserve the tips, making an important contribution to our limited understanding of Later Stone Age bone tool technology

Development of a thermally improved hollow concrete block

The paper is focused on the comparison of the compression strength and thermal insulation of improved prototypes of hollow concrete building blocks to traditional local building blocks, with the aim of developing a new product for the local market that meets the demand for better insulated buildings. The building blocks under test are hollow concrete blocks (HCBs) manufactured by a local company. The heat flow meter method and infrared method techniques are applied to obtain values of the thermal conductivity of the respective HCBs being tested. Dimensions and weight of these blocks have been recorded and compression testing carried out. The correlation between thermal conductivities and compression strengths of the standard and prototype HCBs shall provide useful information on the thermo-physical behaviour of these building elements. The paper reports on the actual setup of the insitu test cells, followed by the description of the material characterisation, the thermal testing methodologies developed and the compression and dimensional testing carried out. The aim is to succeed in obtaining an innovative block with an improved U-value of at least 10% over existing standard local HCBs without reducing the standard minimum characteristic compressive strength of 7.5 N/mm2.Bajada New Energy, Bitmac ltd., Econetique, Energy Investment, JMV Vibro Blocks, Solar Engineering.peer-reviewe

Overview of testing methodologies for thermally improved hollow-core concrete blocks

We acknowledge the co-financing provided by the National Research and Innovation Programme 2012 of the Malta Council for Science and Technology (MCST), under grant agreement R&I-2012-058, as well as the University of Malta for providing the necessary research environment.In construction, hollow-core concrete blocks (HCBs) offer a number of advantages over solid blocks, such as lighter weight and improved thermal and acoustic insulation. However, the relative high value of the overall heat transfer coefficient (Uvalue), makes them less attractive for use in new buildings in Europe, given that these must approach the net-zero energy performance level by 2020. In this respect, a project has been developed in Malta, which aims at producing a new HCB having the same physical dimensions and load bearing characteristics as a standard locally-produced HCB, but with improved thermal properties. The project (ThermHCB) is being co-financed by the Malta Council for Science and Technology (MCST) under the 2012 R&I National Programme. ThermHCB project is divided into a number of Work Packages covering the whole process from developing the HCB, manufacturing, testing and optimizing the final commercial product. This paper focuses on one aspect of this project, namely on the testing methodologies that are being proposed and implemented, for the load bearing as well as thermal characterization of the HCBs. In the latter, two procedures are being adopted to compare the thermal properties of standard and prototype HCBs, using infra-red techniques and heat flow methodology. Comparisons shall be made to verify whether the infra-red method, which offers faster measurement techniques, provides U-value results that are sufficiently accurate.peer-reviewe

MTFuzz: Fuzzing with a Multi-Task Neural Network

Fuzzing is a widely used technique for detecting software bugs and vulnerabilities. Most popular fuzzers generate new inputs using an evolutionary search to maximize code coverage. Essentially, these fuzzers start with a set of seed inputs, mutate them to generate new inputs, and identify the promising inputs using an evolutionary fitness function for further mutation. Despite their success, evolutionary fuzzers tend to get stuck in long sequences of unproductive mutations. In recent years, machine learning (ML) based mutation strategies have reported promising results. However, the existing ML-based fuzzers are limited by the lack of quality and diversity of the training data. As the input space of the target programs is high dimensional and sparse, it is prohibitively expensive to collect many diverse samples demonstrating successful and unsuccessful mutations to train the model. In this paper, we address these issues by using a Multi-Task Neural Network that can learn a compact embedding of the input space based on diverse training samples for multiple related tasks (i.e., predicting for different types of coverage). The compact embedding can guide the mutation process by focusing most of the mutations on the parts of the embedding where the gradient is high. \tool uncovers $11$ previously unseen bugs and achieves an average of $2\times$ more edge coverage compared with 5 state-of-the-art fuzzer on 10 real-world programs.Comment: ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE) 202

Task force IRSPM A&A SIG, CIGAR Network, EGPA PSG XII

The IPSAS CP asks the following questions in its REQUEST FOR COMMENTS. The responses prepared by the Task Force IRSPM A&A SIG, CIGAR Network and EGPA PSG XII are presented hereafter. The IRSPM A&A SIG, CIGAR Network and EGPA PSG XII are three research networks that focus on Public Sector Accounting. The Task Force is made up of 16 researchers from these networks. The responses being presented are based on an analysis of the Consultation Paper, the IPSASB Conceptual Framework, relevant IPSAS, and various published research papers on the subject. Following various meetings and discussions, the members of the Task Force have reached the following common conclusions and suggestions. The views expressed in this document represent those of the members of the Task Force and not of the whole research community represented by the networks, and neither of the Institutions/Universities with which they are affiliated

Influence of socioeconomic factors on pregnancy outcome in women with structural heart disease

OBJECTIVE: Cardiac disease is the leading cause of indirect maternal mortality. The aim of this study was to analyse to what extent socioeconomic factors influence the outcome of pregnancy in women with heart disease.  METHODS: The Registry of Pregnancy and Cardiac disease is a global prospective registry. For this analysis, countries that enrolled ≥10 patients were included. A combined cardiac endpoint included maternal cardiac death, arrhythmia requiring treatment, heart failure, thromboembolic event, aortic dissection, endocarditis, acute coronary syndrome, hospitalisation for cardiac reason or intervention. Associations between patient characteristics, country characteristics (income inequality expressed as Gini coefficient, health expenditure, schooling, gross domestic product, birth rate and hospital beds) and cardiac endpoints were checked in a three-level model (patient-centre-country).  RESULTS: A total of 30 countries enrolled 2924 patients from 89 centres. At least one endpoint occurred in 645 women (22.1%). Maternal age, New York Heart Association classification and modified WHO risk classification were associated with the combined endpoint and explained 37% of variance in outcome. Gini coefficient and country-specific birth rate explained an additional 4%. There were large differences between the individual countries, but the need for multilevel modelling to account for these differences disappeared after adjustment for patient characteristics, Gini and country-specific birth rate.  CONCLUSION: While there are definite interregional differences in pregnancy outcome in women with cardiac disease, these differences seem to be mainly driven by individual patient characteristics. Adjustment for country characteristics refined the results to a limited extent, but maternal condition seems to be the main determinant of outcome

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Une seconde bande dessinée éducative en lutte antiacridienne : les dents du ciel II ou la lutte intégrée contre les criquets en Afrique sahélienne. Intention, réalisation, premiers impacts

Pour atteindre un public plus large que celui habituellement concerné par les articles scientifiques, les manuels pédagogiques ou les ouvrages habituels de vulgarisation, le CIRAD-GERDAT-PRIFAS, ayant noté le très bon accueil de la première bande dessinée éducative en lutte chimique contre les criquets en Afrique sahélienne, a proposé une suite sur le thème de la lutte intégrée en suivant le même héros sahélien de retour dans son village natal. L'objectif poursuivi est de faire comprendre ssur la base de cas concrets ce qu'implique le concept de lutte intégrée et la nécessaire prise en compte des valeurs traditionnelles pour faire accepter de nouvelles solutions aux fléaux acridien