Plastic mechanisms for thin-walled cold-formed steel members in eccentric compression.

The Eurocode 3 concerning thin-walled steel members divides members subjected to compression into four classes, considering their ductility. The representatives of the class C4 are short bars, for which the load-capacity corresponds to the maximum compression stresses less than the yield stress. There are bars prone to local buckling in the elastic range and they do not have a real post-elastic capacity. The failure at ultimate stage of such members, either in compression or bending, always occurs by forming a local plastic mechanism. This fact suggests the possibility to use the local plastic mechanism to characterise the ultimate strength of such members. The present paper is based on previous studies and some latest investigations of the authors, as well as the literature collected data. It represents an attempt to study the plastic mechanisms for members in eccentric compression about minor axis and the evolution of plastic mechanisms, considering several types of lipped channel sections

An evidence based guide to a safe intraoperative approach of avoiding iatrogenic lesions during difficult laparoscopic cholecystectomies

Introduction: Although there are many sources for iatrogenic lesions during laparoscopic cholecystectomy, only a few stand out as being one of the most difficult to predict due to their nature of being very hard to diagnose before surgery. Materials and Methods: a short guide of cases with an evidence-based approach to avoid laparoscopic iatrogenic lesions. Results: these cases have been classified and presented into 3 main groups: cases with abnormal arterial layout, cases with heavy alteration of the normal anatomy, and cases with anomalies of the main biliary pathway. Conclusions: while not a complete guide covering all aspects of intraoperative traps during laparoscopic cholecystectomy, this series of cases points out some dangerous situations and some simple solutions to avoid those fiercely iatrogenic lesions of the ductal and vascular landmarks associated with an otherwise simple surgical intervention that has become the golden standard of the gallbladder lithiasic pathology

MANAGEMENT PRACTICES OFWASTEWATER SLUDGE

Large amounts of wastewater sludge, a secondary pollutant of wastewater treatment plants, commonly containing over 90% water and pathogens, organic pollutants and heavy metals, are produced daily worldwide.  Main treatment routes of wastewater sludge are: landfill, anaerobic digestion, land application and incineration. Anaerobic sludge digestion is a technology employed worldwide to reduce solids, stabilize organic matter, and destroy pathogens and to produce biogas as a source of energy.Compositing is applied for sludge treatment and conversion of complex biowaste into a stabilized product that can be used as organic fertilizer in agriculture. In this paper we present the main practices employed in the management of wastewater sludge, in order to reduce its volume, to capitalize it and to protect the environment

APPLICATIONS OF ROTATING BIOLOGICAL CONTACTORSIN WASTEWATER TREATMENT

Rotating biological contactors are generally used as secondary treatment of domestic, hospital and industrial wastewater, operating asan aerobic and anaerobic fixed film biological treatment. Rotating biological contactors areeffective in the removal of biodegradable matter,pathogenic bacteria,nitrogen, recalcitrant compounds, heavy metals,emerging contaminants, and dyes from wastewater. In this paper, we present the design and operating principles of rotating biological contactors, and we review some of the most important results related to the applications of rotating biological contactors for the treatment of wastewater originating from different activities

NANOMATERIALS FORHEAVY METALS REMOVAL FROM WASTEWATER

Human, agricultural, industrial, and mining activities generate large quantities of wastewater contaminated with toxic and non-biodegradable heavy metals such as As, Cr, Cd, Co, Cu, Hg, Ni, Pb and Zn.To avoid the harmful effects of heavy metals on terrestrial and aquatic ecosystems and on human health, it is essential to develop and implement innovative technologies for the removal of these toxic and hazardous pollutants from wastewater.In wastewater treatment, and particularly in nanotechnology applications, many efficient, ecological and cost-effective nanomaterials have been developed, having unique functions of heavy metals removal from industrial effluents, surface waters, groundwater and drinking water.Due to their antimicrobial properties, nanoparticles are also used for wastewater disinfection and microbial control

Characteristics and tendencies in the steel industry, globally and regionally

The objective of this paper is to highlight the current state of the steel industry at the global and regional level, in terms of its level of important indicators, such as: production capacity, production volume, level of consumption, exports and imports. The data used are systemized on time intervals, resulting in that the steel industry remains an attractive sector for investors in terms of large profits generated, but extremely sensitive to economic fluctuations and measures taken by the authorities. In this regard, the disparities and trends of the analyzed periods at global and regional level highlight the different ways of managing the situation in the steel sector, overcapacity representing a highly controversial element nowadays

π\pi-Electron Ferromagnetism in Metal Free Carbon Probed by Soft X-Ray Dichroism

Elemental carbon represents a fundamental building block of matter and the possibility of ferromagnetic order in carbon attracted widespread attention. However, the origin of magnetic order in such a light element is only poorly understood and has puzzled researchers. We present a spectromicroscopy study at room temperature of proton irradiated metal free carbon using the elemental and chemical specificity of x-ray magnetic circular dichroism (XMCD). We demonstrate that the magnetic order in the investigated system originates only from the carbon $\pi$-electron system.Comment: 10 pages 3 color figure

Further insights on predictors of environmental tobacco smoke exposure during the pediatric age

Background: The smoking ban in public places has reduced Environmental Tobacco Smoke (ETS) exposure for non-smokers, but despite this, domestic environments still remain places at high risk of exposure, and, today, about 40% of children worldwide are exposed to ETS at home. The aims of the study are to investigate the contribution of several factors on ETS exposure among a group of Italian children and to evaluate the changes in smoking precautions adopted at home when the smoker is the mother, the father, or both parents, respectively. Methods: A cross-sectional study was performed on a sample of 519 Italian schoolchildren. Information was collected via a questionnaire. Results: 41.4% of the participants lived with at least one smoker. Almost half of the children exposed to ETS lived with one or more smokers who do not observe any home smoking ban. Lower maternal or paternal educational levels significantly increase the risk of ETS exposure at home and the “worst case” is represented by both parents who smoke. Conclusions: More effective preventive interventions are needed to protect children from ETS exposure. Some interventions should be specifically dedicated to smokers with a low educational level and to mothers that smoke

Pregnancy monitoring

International audienc