نتایج جستجو برای: crystalline silica
تعداد نتایج: 75815 فیلتر نتایج به سال:
OBJECTIVE Isolation of potentially pathogenic bacteria from carpets in hospitals has been reported earlier, but not from carpets in mosques. The aim of the present study is to determine the pathogenic and potentially pathogenic bacteria that may exist on the carpets of mosques in Tripoli, Libya. METHODS Dust samples from carpets were collected from 57 mosques in Tripoli. Samples were examined...
Membrane-based gas separation processes can address key challenges in energy and environment, but for many applications the permeance and selectivity of bulk membranes is insufficient for economical use. Theory and experiment indicate that permeance and selectivity can be increased by using two-dimensional materials with subnanometer pores as membranes. Motivated by experiments showing selectiv...
In this paper, we bring forward an effective strategy, solvothermal postsynthesis, to prepare ordered mesoporous silica materials with highly branched channels. Structural characterizations indicate that the titled mesoporous materials basically have the cubic double gyroidal (space group Ia-3d) structure with small fraction of distortions. The mesopore sizes and surface areas can be up to 8.8 ...
Construction dust is one of the most concerned pollutants presenting risks to human health. Dust from construction activities, particularly true for silica dust, have an adverse effect on the local environment and on the health of local residents, as well as on those working on the site. There is a long-term concern about the over exposure of construction workers to respirable crystalline silic...
Silica aerogels are porous and extremely lightweight nano-materials shows interesting properties. These materials, because of biocompatibility, non-harmful to the body and special physical characteristics such as large surface area and low density have great potential for use in a drug delivery system (DDS). The focus of this study is the evaluation of the effects of silica aerogels on improvin...
Silica-clad optical fibers comprising a core of crystalline germanium were drawn using a molten core technique. With respect to previous fibers drawn using a borosilicate cladding, the present fibers exhibit negligible oxygen despite being fabricated at more than twice the melting point of the germanium. The counterintuitive result of less oxygen when the fiber is drawn at a higher temperatures...
This study investigated occupational exposure to silica dust of 48 workers in stone cutting, glass making, ceramic, and sand blasting plants in the north of Iran. Samples were collected from the breathing zone using a personal sampling pump and a size-selective cyclone. Sample filters and blanks were analysed using infrared spectroscopy. The mean sampling period was 4.83 h. Mean exposure of wor...
The extra demand imposed upon the Libyan health services during and after the Libyan revolution in 2011 led the ailing health systems to collapse. To start the planning process to re-engineer the health sector, the Libyan Ministry of Health in collaboration with the World Health Organisation (WHO) and other international experts in the field sponsored the National Health Systems Conference in T...
PURPOSE There is a substantial body of research that utilizes saliva cortisol levels to examine wartime stress; however, there is a paucity of literature that utilizes hair cortisol levels, which allows for long-term assessment of chronic stress, to investigate the stress of war. The present study aimed to evaluate changes in hair cortisol concentrations before, during, and after the 2011 Libya...
A quantitative determinants-of-exposure analysis of respirable crystalline silica (RCS) levels in the construction industry was performed using a database compiled from an extensive literature review. Statistical models were developed to predict work-shift exposure levels by trade. Monte Carlo simulation was used to recreate exposures derived from summarized measurements which were combined wit...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید