74 research outputs found
Twentieth century Iranian carpets: investigation of red dye molecules and study of traditional madder dyeing techniques
Abstract Red is undoubtedly one of the principal colors in Iranian carpets. During the twentieth century, a golden era for Iranian carpet production and export industry, madder was still one of the primary constituents of the red dyestuff, used according to various dyeing methods which is specific for Iran. Compared to the earlier periods, the said period witnessed a clear increase in the hues of the color red and in the alternation of physical and visual properties. We, therefore, aim to get a better insight into the chemical and physical properties of the component which made it all possible—dyes. To this effect, eighteen red wool samples with various hues were collected from seven Iranian carpets belonging to the aforementioned period (from Ali Mirzaei's private collection) and analyzed using three techniques: reversed-phase-high-performance liquid chromatography (RP-HPLC-DAD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) and colorimetry. We also studied traditional dying recipes to underpin the scientific process involved. We focused on recipes based on madder, which are mordanted with organic additives such as qarehqurut (a kind of Iranian dairy product; also known as Gharehghorut). These substances, additionally, helped control the acidity of the dyebath; a common technique from the period. The effect of these substances on the hue, the associated red dye chemistry, various visual and physical properties, including color fastness, are reported. Our study revealed, among other facts, that the additive qarehqurut is highly efficient at improving color absorption and at increasing lightfastness. Another salient finding was that, besides madder, various synthetic dye sources were used by the twentieth century "traditional" Iranian red dyeing industry
Indoor Air Quality in Health Care Units (Case Study: Namazi Hospital, Shiraz, Iran)
Indoor air quality (IAQ) represents an important research focus due to its direct and substantial implications on human health outcomes. Existing research showed that substandard IAQ exacerbates the effects of airborne diseases. The objective of this chapter would be to explore the correlation among indoor air quality (IAQ), location of air outlet valves, and fluctuations in IAQ indicators within the cardiovascular care unit (CCU). In this regard, a combination of experimental and numerical methods has been utilized. These included direct IAQ measurements within the unit and the application of computational fluid dynamics to simulate indoor air conditions based on the collected experimental data. In this specific circumstance, the state of the air outflow valve and the condition of the air change rate significantly affect the enhancement of IAQ levels. To confirm this hypothesis, existing literature was thoroughly reviewed according to IAQ guidelines. In a similar vein, the study included measurements of emissions such as CO2, CO, PM2.5, and PM10. Additionally, it examined the association relating to IAQ, air outlet placement, and dynamics of the emissions within the patient’s room
Emergency Department Bedside Ultrasonography for Diagnosis of Acute Cholecystitis; a Diagnostic Accuracy Study
Introduction: Using bedside ultrasound in diagnosing acute cholecystitis in the emergency department (ED) can save time, help the decision making process and allocate resources wisely. This study aimed to evaluate the diagnostic accuracy of bedside right upper quadrant (RUQ) ultrasonography in detection of acute cholecystitis. Method: In this diagnostic accuracy study, patients presenting to ED, suffering from RUQ pain in favor of acute cholecystitis underwent RUQ ultrasonography in emergency and radiology departments and interrater agreement between reports was calculated. Results: 342 patients with the mean age of 53.92 ± 11.18 (20 – 83) years were studied (63.2% female). The number of patients with at least one sonographic finding of acute cholecystitis were 53 (15.50%) and 48 (14.00%) based on ED and radiology reports (Kappa = 0.826). Sensitivity, specificity, positive and negative predictive values, as well as positive and negative likelihood ratios of bedside sonography were 89.58 (95%CI: 76.55 – 96.10), 96.59 (95%CI: 93.63 – 98.29), 81.13 (95%CI: 67.58 – 90.11), 98.26 (95%CI: 95.77 – 99.36), 4.30 (95%CI: 2.42 – 7.62) and 0.017 (95%CI: 0.007 – 0.041), respectively. Conclusion: There was a very good agreement between ED and radiology departments’ sonography reports regarding the presence or absence of acute cholecystitis. Sensitivity and specificity of bedside RUQ sonography were 89.58 and 96.59, respectively
Statistical Analysis on IoT Research Trends: A Survey
Internet of Things (IoT) is a novel and emerging paradigm to connect real/physical and virtual/logical world together. So, it will be necessary to apply other related scientific concepts in order to achieve this goal. The main focus of this paper is to identify the research topics in IoT. For this purpose, a comprehensive study has been conducted on the vast range of research articles. IoT concepts and issues are classified into some research domains and sub-domains based on the analysis of reviewed papers that have been published in 2015 & 2016. Then, these domains and sub-domains have been discussed as well as it is reported their statistical results. The obtained results of analysis show the most of the IoT research works are concentrated on technology and software services domains similarly at first rank, communication at second rank and trust management at third rank with 19%, 14% and 13% respectively. Also, a more accurate analysis indicates the most important and challenging sub-domains of mentioned domains which are: WSN, cloud computing, smart applications, M2M communication and security. Accordingly, this study will offer a useful and applicable broad viewpoint for researchers. In fact, our study indicates the current trends of IoT area
Experimental and numerical investigation of hole and edge radius effect on collapse properties of cylindrical absorbers under axial impact loading
In this paper, the collapse properties of aluminum cylindrical tubes that hole or curvature is created on their edges or their mid is studied in experimental and numerical methods. The tubes were put under axial impact of a rigid mass-block of 30.405 kg by an initial velocity of 6 or 7 m/s. In experimental exams, first the type of aluminum alloy and mechanical properties of tubes were determined, and then four samples in order to validating the numerical results were analyzed under Impact collapse. An explicit FE code, LS-Dyna, was used to implement numerical investigation and a total of 13 specimens were examined. In results and discussion it was found that in impact loading, creating hole and curvature in edge and mid of cylindrical shells while keeping energy, decreases maximum force significantly and increasing crush force efficiency. In general, by increasing the number of holes, the less maximum force and more crush force efficiency. It was observed that in impact loading, establishment of curvature at the edges, reduces the maximum force and absorption energy and raises the crush force efficiency so that by raising edge curvature radius, maximum force and absorption energy decrease but crush force efficiency increase. Finally samples with optimal performance for each type of perforated and curved edge energy absorbers were introduced. These absorbers can be an appropriate alternative for usually types
Twentieth century Iranian carpets: investigation of red dye molecules and study of traditional madder dyeing techniques
Red is undoubtedly one of the principal colors in Iranian carpets. During the twentieth century, a golden era for Iranian carpet production and export industry, madder was still one of the primary constituents of the red dyestuff, used according to various dyeing methods which is specific for Iran. Compared to the earlier periods, the said period witnessed a clear increase in the hues of the color red and in the alternation of physical and visual properties. We, therefore, aim to get a better insight into the chemical and physical properties of the component which made it all possible\u2014dyes. To this effect, eighteen red wool samples with various hues were collected from seven Iranian carpets belonging to the aforementioned period (from Ali Mirzaei\u2019s private collection) and analyzed using three techniques: reversed-phase-high-performance liquid chromatography (RP-HPLC-DAD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM\u2013EDX) and colorimetry. We also studied traditional dying recipes to underpin the scientific process involved. We focused on recipes based on madder, which are mordanted with organic additives such as qarehqurut (a kind of Iranian dairy product; also known as Gharehghorut). These substances, additionally, helped control the acidity of the dyebath; a common technique from the period. The effect of these substances on the hue, the associated red dye chemistry, various visual and physical properties, including color fastness, are reported. Our study revealed, among other facts, that the additive qarehqurut is highly efficient at improving color absorption and at increasing lightfastness. Another salient finding was that, besides madder, various synthetic dye sources were used by the twentieth century \u201ctraditional\u201d Iranian red dyeing industry
Fungi isolated from the skin lesions of Ghezel and Makui sheep with suspected ringworm in Urmia, Iran
Non-dermatophytic fungi are frequently isolated on the cultures used in surveys of animals suspected of having ringworm. The present study was conducted to identify of saprophytic fungi and dermatophyte isolated from sheep with suspected ringworm in Urmia, Iran. A total of 1323 sheep from two breeds of Ghezel (n = 727) and Makui (n = 596) were examined for skin lesions. Only 4(0.035 %) lesions with hair loss and scaling were found on ears of Ghezel sheep. Samples were examined microscopically by KOH and cultured ontoSabouraud’s dextrose agar and Sabouraud’s dextrose with chloramphenicol and cycloheximide, incubated at 25 and 37 ° C and examined for 4weeks. All (100%) of the specimens yielded positive culture. Fungal isolates were Alternariaspp. (3 cases, 75 %) and Mucor spp. (2 cases, 50%). No dermatophyte fungi were cultured from suspected ringworm lesions. Saprophytic fungi isolated in the present study may not be considered as cause of skin lesions in Ghezel sheep
Parametric investigation of the mechanical behavior of expanding-folding absorbers and their implementation in sandwich panels core
Thin-walled energy absorbers are one of the common structures that are used in vehicle body for increasing the crashworthiness and consequently decreasing injuries. Investigated new type of thin-walled aluminum matrix and a thin-walled steel punch energy absorber structure has been investigated in this paper. Energy is absorbed as the matrix expansion followed by simultaneous matrix and punch folding. Present study proposes a sandwich panel based on expanding-folding absorber units to evaluate their crush mechanism. Parametric study has been done using finite element code LS-DYNA while experimental tests have been implemented to validate the FE model. The panels have been tested under three axial quasi-static loading conditions including a rigid half-cylinder and a rigid plate. Parametric study considers the punch angle, matrix thickness and punch thickness. The optimum structure based on energy absorption has then been used as a structural member in the sandwich panel until a panel with high specific energy absorption be introduced. Also it have been seen that all the curves for the expansion section can be estimated using polynomial second order functions, with a high accuracy
Evaluation of Artificial Lighting and its Relationship with Body postures During Work in Hamadan Women\'s Hairdressers
Background and objective: long term work, nonstandard and improper tools, and inadequate lighting in the workplaces are important factors which resulted in awkward postures in hairdressers. The present study was performed to assess general and local lighting and investigate its relationship with postural status assessed by Rapid Entire Body Assessment (REBA) method in Hamadan’ hair salons.
Material and methods: in this descriptive analytical study, 100 hairdressers who worked in 50 hair salons were studied. The local and general lighting was measured using a Hanger ESI photometer. The hairdressers’ postures were assessed using REBA method. Data were analysed using version 21.0 of the SPSS/PC statistical package.
Results: in 97 and 72% of the studied hair salons, local and general illuminance levels were lower than the occupational exposure limit, respectively. REBA assessment indicates that 26 and 12.5% of the studied subjects fell in to high and very high risk levels, respectively. ANOVA test showed significant relationship between general illuminance and the REBA scores in face and eyebrow makeup tasks (p<0.05).
Conclusions: in most of the hair salons, local and general illuminance was lower than the Iranian occupational exposure limit and it had not a suitable condition in term of quality and quantity. According to the obtained risk levels, the modification of lighting systems of the hair salons and training of the hairdressers are recommended to prevent ergonomic disorders in hairdressers. 
A parametric study of the mechanical behavior of nested multi tube structures under quasi-static loading
Mechanical behavior of nested aluminum structures under lateral and quasi-static loadings has been investigated in current paper. These structures consist of two nested tubes in which the inner tube is located vertically in the horizontal outer tube. The research has been done numerically and experimentally. In the numerical section, the LS-DYNA software has been used while experimental results are implemented to validate the FE outcome. The well correlated numerical results show that increasing the diameter of the inner tube leads to a decrease in the maximum force and the specific energy absorption. Later, employing the optimization by response surface method in Minitab software, the energy absorber's characteristics has been optimized and introduced as new set of specifications. High crush force efficiency is the main criterion in current research
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