فهرست مطالب مسعود ضیایی

The occurrence of fire in structures is a possible phenomenon that can significantly affect the mechanical properties of the materials of structural members. Nowadays, the use of new materials and additives in concrete construction has been considered, and it is necessary to examine the strength of concrete made with these materials during and after fires and to ensure its proper behavior. In this research, microsilica, as a very effective pozzolanic material and polypropylene fibers as a material to improve cracking resistance were used to make concrete. The behavior of concrete specimens with different values of these additives after exposure to high heat was investigated in the form of tensile and compressive strength tests. The control concrete specimen was considered for comparison with other specimens where the compressive strength of this specimen was 30 MPa. In addition to the control specimen mixing design, 11 other mixing designs were made with propylene fibers in the amount of 0.05, 0.075 and 0.1% of the weight of concrete and microsilica in the amount of 5%, 10% and 15% of the weight of cement. The specimens were placed in an oven at 600 ° C for one hour. After cooling, compressive and tensile strength tests were performed on the specimens. The results showed that the combination of polypropylene and microsilica fibers increased the tensile strength, the maximum increase was 82% compared to the control specimen. The maximum increase in compressive strength compared to the control specimen was 63.4%. After exposure to heat, the tensile strength of the proposed sample increased by 44% compared to the control specimen.

Tires and waste glass are long-lasting pollutants in nature. One of the ways to recycle waste glass and rubber is to use it in concrete, which will result in minimal extraction of natural minerals. Many engineering structures are exposed to fire hazards, and therefore it is necessary to know the mechanical properties of concrete materials at high temperatures. In this research, waste glass and rubber were used as a substitute for a part of natural fine grain (sand). The size of glass particles is between 0.2-0.85 mm and with percentages of 5%, 10% and 15% and the size of rubber particles is between 3-5 mm by volume and with percentages of 5% and 10%, replacying fine aggregates. In total, 12 mixing plans were made, and from each mixing plan, 3 cubic and cylindrical specimens were made with different percentages of glass and rubber. The compressive and tensile strength, workability, weight loss, ratio of residual compressive and tensile strength of the specimens were measured at ambient temperature and at 600 °C and the average values were evaluated. In terms of appearance, after applying heat, the color of the specimens became darker and hairline cracks were widely visible on the concrete surfaces. As expected, with increasing the rubber, the compressive strength of the speciemns decreased. After applying heat, the resistance drop of all specimens was higher than the ambient temperature state. With the increase in the rubber, the resistance decreased more, which can be attributed to the burning and destruction of rubber particles and the appearance of small holes and porosity in concrete. With increasing glass percentage, the trend of compressive strength was slightly improved. The results showed that the combined design of 5% glass and 5% rubber is the optimal design and has a more appropriate performance than other designs.

With the advancement of technology in the world, industrial waste has become one of the most important environmental challenges. Deformation and reuse of these wastes is one of the ways to improve the sustainable state of the environment. Glass and rubber are among the most widely used materials in the world, which due to their nature have a lot of wastes. Waste tires cause a lot of environmental pollution due to their non-degradable materials. The use of waste glass and rubber in the construction industry can be a good solution in reusing waste materials. Concrete, on the other hand, is one of the most widely used materials in the construction industry, and the addition of rubber and glass crumb to concrete can improve some of its mechanical and dynamic properties. Of course, heat resistance of materials is one of the features that is effective in the type of application. Adding waste rubber and glass to concrete, of course, depending on their amount and size can increase the heat resistance of concrete to some extent.
In this research, the effect of replacing small and large aggregates with rubber and also glass powder with cement in concrete at ambient temperature and high temperature has been studied. The size of rubber used in concrete in two categories is 1 to 3 mm and 5 to 10 mm, which are replaced by fine-grained and coarse-grained, respectively, with replacement values ​​of 0, 5 and 10%. The size of the glass used is smaller than 75 microns and it can be replaced with cement with 0, 10, 15 and 20% replacement values. Shredded truck tires and powdered construction glass were used. In this study, cubic specimens were made into 15 x 15 x 15 cm specimens and cylindrical specimens with a diameter of 15 cm and a height of 30 cm were made according to the standards and processed for 28 days in optimal conditions. After processing, the number of cubic and cylindrical specimens was subjected to compressive and tensile tests. A number of other samples were placed in an electric furnace and heated to 600 ° C as standard. After removing the samples from the furnace, they were naturally placed at room temperature for 24 hours and then they were tested for the Residual compressive and tensile strength. The microstructure of concrete containing glass and rubber was examined by scanning electron microscope (SEM). The results of this study showed that adding rubber and glass to concrete causes a decreases compressive strength and increases tensile strength. The D10C10 design, which has the highest compressive strength, has a resistance reduction of about 12% compared to the reference design. The highest tensile strength of heated samples is related to D5C15 design, which is about 43% higher than the heated reference design. By comparing the sum of heated and unheated samples, it can be seen that heat at 600 ° C has reduced the compressive strength by an average of about 33%. In general, concrete made with 10% replacement of rubber instead of coarse in unheated samples and 15% glass instead of cement in heated samples showed better properties. Also, in the study of concrete microstructure, adhesion between rubber and concrete was appropriate.

One of the recycling approaches for waste materials like tires and glass is to use them in concrete. In this paper, the effect of the simultaneous use of waste rubber as partial substitution of fine aggregate and glass powder as partial substitution of cement, on workability and mechanical properties, in ambient temperature and after exposure to temperature of 600 °C, is investigated. In order to evaluate the effect of rubber particle size on workability and mechanical properties, two different rubber particle sizes of 0.15-1mm and 3-5mm were used. In total, 13 mixtures were prepared. Except for the reference mixture, the rest contained a combination of rubber particles replacing fine aggregate with the percentages of 5% and 10% by volume and glass powder replacing cement with percentages of 10%, 15% and 20%. First of all, the slump test was carried out. Moreover, compressive strength and tensile strength, before and after thermal exposure, were investigated. In order to have an understanding of waste material's behavior, scanning electron microscopy and energy-dispersive X-ray spectroscopy tests were conducted. the results indicated that 5% for rubber particles, 10% for glass powder and also rubber particle size of 3-5 mm presented the best results among mixtures containing rubber and glass powder, in terms of compressive and tensile strengths.

Reinforced concrete structures on the shores of the Persian Gulf experience a severe corrosion environment, and in the case of the structures that are in tidal conditions or some of their members are submerged in the sea, such as piers and ports, this problem is more acute due to the penetration of chloride ions. To increase the efficient life of concrete structures in the Persian Gulf, the use of self-compacting concrete along with cement substitutes has been suggested by researchers. In this paper, two powdered materials, slag and micro-silica, have been selected to replace part of the cement content in concrete. The durability test in submerged and tidal conditions has been performed on the specimens. Based on the results of experiments on 216 concrete specimens, the use of the proposed concrete on average increases the compressive strength by 22%, electrical resistance by 50% and decreases the permeability of volumetric water absorption by 12% and capillary water absorption by 30% in tidal conditions.

Early diagnosis and treatment are crucial for the survival of severe Coronavirus Disease 2019 (COVID-19) patients. Various studies have shown the clinical characteristics of patients admitted to COVID-19 hospital. However, the predictors of the results are still unclear. Our objective was to investigate the presence of potential risk factors associated with disease severity progression in the natural history of COVID-19.

The present study is a retrospective monocentric study. In which part of patients with Covid-19 South Khorasan who are hospitalized in Valiasr Hospital in Birjand (except for patients who are in the very first stage of triage, in a very severe stage of the disease). They were examined and their symptoms were recorded. The information of patients who enter a very severe and critical stage of the disease and are transferred to intensive care units will be separated and patients will be divided based on clinical indicators. Finally, clinical, laboratory and therapeutic data from 111 patients admitted to Valiasr Hospital in Birjand were collected and analyzed with the approval of COVID-19 laboratory and the data collected from discharged and critically ill patients were compared.

Of these 111 patients, 93 were discharged and 18 entered the acute phase of the disease. The number of lymphocytes (0.56 G / L vs. 1.3 G / L was lower in the exacerbated group than in the discharged group. The number of involved lung lobes was 5 vs. 4). Multivariate analysis showed that comorbidity [ (OR) 52.6, 95% confidence interval (CI) 3.6–776.41], Sex (OR 24.8, 95% CI 1.8–342.1) were independent risk factors for disease severity in COVID-19 patients. Our results also show that CT intensity score is associated with the level of inflammation, and older age, higher neutrophil to lymphocyte ratio (NLR) and CT intensity score at the time of hospitalization are other independent risk factors affecting the short-term progression of the Covid virus. 19 are in these patients.

The results of this study facilitate the early identification of high-risk COVID-19 patients. These findings can be useful in predicting the risk of progression in patients with COVID-19 at the time of admission. A CT scan may help classify the risk.

One of the most common complications of diabetes is diabetic foot ulcer, which exposes patients to wound infection, osteomyelitis, and lower-limb amputation if left untreated. Therefore, accurate and rapid diagnosis of wound and osteomyelitis infection is an important step in treating this debilitating complication. In this regard, the present study was aimed to determine the incidence of osteomyelitis and assess its risk factors in patients with diabetic foot ulcers during 2013 and 2016 in Birjand, Iran. This epidemiological analytical-retrospective study was conducted using numerical sampling. Demographic and clinical data were obtained by reviewing patients’ medical records and using a checklist developed by the project manager. Data analysis was performed using SPSS software (version 18). Quantitative and qualitative results were reported as mean±standard error and percentage, respectively. The obtained findings indicated a significant association between the location of foot ulcers and the risk of osteomyelitis (P=0.02); accordingly, osteomyelitis is more likely to occur in diabetic ulcers on the toes. However, no significant difference was observed between right and left foot ulcers in terms of osteomyelitis risk. Mean erythrocyte sedimentation rate was also significantly higher in diabetic patients with osteomyelitis than those of non-osteomyelitis ones (P=0.04). However, no significant difference was observed in C-reactive protein and leukocytosis. The age and gender of the patients had no significant effect on the risk of osteomyelitis. Overall, the results of the present study demonstrated a significant relationship between the location of foot ulcers and the probability of osteomyelitis. Accordingly, ulcers located on the toes are more likely to develop osteomyelitis.

Considering the increasing hostile and terroristic threats in the country, it is important to consider the passive defecncecriteria in structures. The desirable properties of steel and concrete cab be used simultaneously to increase the strength of structural members. Concrete-filled steel tube columns (CFSTs) have been proposed as an efficient system in the previous years. The main problem with using this type of column is how to connect the beam to such a column and extensive researches has been done for seismic load scenarios. Despite the excellent resistance of these types of columns to the blast load, no comprehensive investigation has yet been conducted on the performance of beam-to-column joints under blast load. In this paper, the behavior of three types of beam-to-column connections under 5 blast scenarios is investigated. ABAQUS software was used to conduct the research. Verification was first performed using the results of an experimental study and a good agreement was observed. The behavior of beam-to-column blast-loaded connections was investigated using 16 different models using explicit nonlinear dynamic analysis. The results were compared in terms of stress, strain and damage contour as well as force, energy absorption, displacement, rotation and torsion diagrams. It was observed that when the connection was carried out as an extension of the beam inside the column, all parts of the column contributed in the load carrying and energy absorption and very good behavior was observed. In this case, the plastic joint in the beam is formed away from the column face.

The walls placed in structural frames can act as a loading surface against the explosion load and significantly increase the dynamic load applied to the structural members. Therefore, the durability of the walls against the blast load and how they are connected to the structural members may have a significant effect on the dynamic response of the structures to the blast load. To investigate this subject, finite element method and Abaqus software are used. Initially, to ensure the accuracy of the predictions of finite element model, verification is performed by modeling an explosive experiment on a concrete-filled steel tube column and a good agreement is observed. Then, the effect of the presence or absence of a concrete wall in the frame and how it is connected to the beam and column is investigated using dynamic explicit analysis. The results of the study showed that in the case of no wall and in the case where the wall is attached to the column only, the highest amount of plasticity has occurred in the beam. In specimens with wall-to-column connection, the maximum plastic strain is observed at the base of the column. The existence of infill wall and the attachment to a beam or column has a significant effect on the vertical displacement of the beam.

Hematological values ​​in people are affected by various factors such as race, environment, time, test method, sample collection site, and age. Given the fact that these factors can differ with each other in different populations, these differences can lead to differences in the results of hematological reference rates. Therefore, we decided to identify a normal range of blood factors in a large sample of the adult population living in South Khorasan. In this cross-sectional study in 2015, a crowd of 5,000 selected from cluster-based adults in Birjand in 2015 and hematological parameters were determined in 4360 healthy subjects. Finally, the data were described using descriptive statistics. The counts for the total white blood cells, red blood cells, Hemoglobin, Hematocrit, and Mean cell volume values ​​for males and females were determined. The mean Hemoglobin values ​​were 15.01 ± 3.13 and 14.01± 1.8 in male and female respectively and the mean Hematocrit was 45.81± 7.52 and 42.59± 5.99 in males and females, respectively. The minimum leukocyte counts were lower than those reported in existing references. However, a higher rate of Eosinophil and Monocyte was obtained among the subjects. Although in general, hematological factors in Southern Khorasan are similar to the values mentioned in other references, but in some cases, there are also differences that can be useful in evaluating them.

According to the strategic geographic position of IRAN with the probability of terrorist threats and air strikes, and also the important crucial role of the tanks, their construction by taking passive defense measures and considerations is necessary. Because of few researches on the vulnerability of tanks against the loads due to explosion, investigate the importance of this type of structures against blast loads is increasing. In present study a hypaethral cylindrical concrete tank, exposed to air blasting by one cubic explosive TNT with weight of 352.08 kg has been modeled. The tank is modeled in four situations such as: empty state, , and of body height full of liquid. The results of simulation showed that damages of compressive and tensile in the empty tank are more critical than other modes, and the manner of hypaethral concrete tanks against explosive loads is different from their manner against seismic loads caused by the earthquake. It was also shown that the conwep method has considerate only the effects of the explosion and at least 25% reduction achieved in compressive damage compared with the results of the AUTODYN. The results of this study can be used in retrofitting and safe design of fluids storage tanks to resistance against the blast loads.

Considering passive defense in construction and rehabilitation of military and residential structures is a proper method for blast-induced damage mitigation. In this paper، the behavior of end plate bolted connections under blast is studied. To assure the accuracy of finite element models، verification is carried out using the results of an experimental test.. A 5-story structure is designed according to national steel structures code using ETABS and one of the first storey connections is studied under blast load using nonlinear dynamic analysis in ABAQUS considering the effects of high strain rates. The results show that the beam experiences significant torsion. Moreover، the critical area in moment connection is the area adjacent to lower bolt holes as well as the area between end plate and lower beam flange. It is also observed that the use of small bolts in higher number provides more desirable response in blast loading.

The aim of educational evaluation is to improve learning and create a suitable situation for academic staff. The present study was performed to assess the viewpoints of BUMS teachers and students regarding the evaluation plan and the effect of it on educational development. The present study was a cross-sectional and descriptive-analytical one. It was performed in the second half of the academic year 2008-9 in Birjand University of Medical Sciences. The study sample included 79 faculty members and 321 paramedical and nursing students. Their opinions were separately studied using two questionnaires for students and faculty members. Content validity and reliability of the two questionnaires employed were confirmed by respective specialists. The gathered data was analyzed by means of SPSS software (V: 16) and Chi-square at the significant level α≤0. 05. It was found that 76 % of faculty members believed that evaluation had some positive effects leading to the betterment of the process of teaching. But، %74. 7 of them believed that some changes in the process should take place. Besides، %69. 9 of the faculty members thought that the questionnaires were irresponsibly and carelessly filled out by the students. On the other hand، %59. 5 of the students believed that the results of the evaluation were not considerably taken into account. They believed that evaluation forms were not suitable evaluative means for teaching. The results of the present study showed that most of faculty members and students are not optimistic about evaluation plan. Therefore، assuring students and teachers of the effectiveness of evaluation regarding the improvement of educational condition will result in more responsibility in students and more motivation in their teachers.

CRP is the main acute phase protein in humans and plays a key role in host defense against infections. This protein is increased in many infections، inflammatory arthritis، autoimmune diseases، neoplastic diseases، pregnancy and elderly this study was done on 400 serum samples that CRP was checked with 3 different kits with slide agglutination method and with photometric method for each sample. Results were compared with quantitative results in photometric method. statistical results in evaluating 400 serum samples with Anisan، Kimia pajohan and Shim enzyme kits were like below: false negative results were detected in 21، 20 and 33 samples respectively. Sensitivities were 87. 6%، 86. 2% and 80. 5% respectively. Specificities were 84%، 74. 1% and 80% respectively. Positive predictive values were 80%، 65. 4% and 74. 7% respectively. Negative predictive values were 90. 2%، 90. 5% and 84. 9% respectively. Although Anisan kits have higher sensitivity، specificity and positive predictive values among these three Iranian kits with slide agglutination method، it is advised to use quantitative methods like ImmunoturbidImetry or photometry because of high frequency of false results in agglutination method.

The elderly form a large sector ssof the human population worldwide. Aging is a risk factor for morbidity and mortality and infectious diseases are among the important causes of morbidity and mortality in this group. The present study aimed at determining the reasons for the hospitalization of the elderly in the infection wards and type and prevalence of the infections which necessitated their hospitalization. In this descriptive analytical Cross-sectional study 350 patients (≥65 yrs) that were admitted to infectious diseases ward of Vali-e-Asr hospital were evaluated. By using questionnaire personal information, the first and ultimate diagnosis of the disease, and characteristics and remedial knowledge of the patients (including the history of previous and contemporary diseases, history of hospitalization, and recent medicines taken) was gathered. The obtained data was analysed by means of SPSS software (version 13) and the statistical Chi-square test at the significant level P<0.05. Result s: 40% of these patients had a previous hospital admission history and 60% of them had been admitted to the hospital for the first time. 56.5% of patients had a history of underlying disease(s), the most common reason of which was hypertension (38.4%). The most common complaints of patients were coughing and dyspnea with abdominal pain. The most common primary diagnosis was pneumonia (27.1%) and as a final diagnosis pneumonia was the most frequent one (52%). A significant difference in the frequency of the final diagnosis in different seasons was observed. The most frequent diagnosis in the spring, autumn and winter was pneumonia and gastroenteritis was the most common final diagnosis reported in summer. Infections in the elderly require a comprehensive review of the previous history of hospitalization and comorbidities. More attention to specific organs including the respiratory, gasterointestinal and urinary tract as the most common organs involved in the diseases in the elderly can help physicians to diagnose the causes of infections in this group more rapidly.

Considering the terrorist and hostile threats against Iran and the dire need of passive defense in structures to reduce casualty and financial damage caused by implosion and explosion in structures, reviewing the performance of structures against blast is of utmost importance. One of the most important structural members which severely affect the overall performance of the structure is the connection of pole to the pillar. The inappropriate performance and defect of these connections can contribute to the surface and in subsequent steps cause the increasing defect in structures and its collapse. In this article, the blast loading effect on the performance of connections of pole to twist shielding pillar has been studied. This kind of connection is used in steel structures in Iran. To do the research, the Limited Elements Method and the ABAQUS software which is one of the most robust Limited Elements Method that exists today was used. To ensure the results of Limited Elements modeling, the authenticity of the model using the results of a laboratory research was first utilized and an appropriate compliance between the predicted results by the Limited Elements Method and the measured results in the laboratory were observed. After ensuring the precision of the Limited Element in the simulation of the connection behavior, a non-linear dynamic analysis taking into account the effects of high rate strain resulting from blast, was performed. Due to the presence of symmetry, only 1/8 of the room was studied for the modeling. The weight of the explosive approximated 15 kilograms of TNT. The test results showed that the occurrence of blast inside the room causes a twisting deflection in the pole. It was also noticed that this kind of connection has a relatively formable behavior against blast loading.

Crimean–Congo hemorrhagic fever (CCHF) is a zoonotic viral hemorrhagic disease, which can be seen in Asia, Africa, East Europe and the Middle East. Mortality rate of this disease is about 30% which can be reduced with timely diagnosis and treatment with Ribavirin and supportive care. In this paper, two confirmed and one suspected cases of CCHF are introduced. Three days after the death of a woman with Disseminated Intravascular Coagulation (DIC) in the infectious diseases ward, a nurse working there and a housewife living in the city of Birjand, had been referred with vaginal bleeding. With suspicious to CCHF, both of them underwent oral treatment with Ribavirin and broad-spectrum antibiotics. The first case had expired in ICU before performing CCHF diagnostic tests; but in the latter two cases the disease was confirmed through molecular tests. The nurse refused to hospitalize and used self-medication at home. However, five days after the symptoms started, she referred to the hospital with a bad general health status, vaginal bleeding and low consciousness and eventually died of this disease. But the second patient recovered after receiving a dose of drug and supportive measures and discharged with a good general health status.

Abnormal loads induced by blast or impact results in local damages in structures and these local damages may propagate and affect whole structural system. Therefore, structures should be designed in a way that progressive collapse is prevented. Connections have important effect on ductility and strength of structural systems and preventing progressive collapse. Consequently, the behavior of bolted angle connection under blast load is studied in this paper using finite element method. In this study, top and seat bolted angle connection with web angles is investigated using ANSYS finite element software. The models are verified comparing the analysis results with those of experimental tests. The verified models are then exposed to blast load and their behavior is evaluated. Critical areas are determined in the connection and failure modes and applicability of mentioned connections against blast loading is investigated.

Salmonella is one of the common bacterial pathogens between man and birds throughout the world. Inconsistent Salmonella contamination following consumption of eggs, as one of the main contributors of the disease has also become an important public health issue. The aim of this study was to investigate prevalence of Salmonella contamination in locally-produced eggs in Birjand in 2006. In this cross-sectional study, raw non industrialized eggs in Birjand were evaluated for Salmonella contamination. A total of 500 samples were purchased from retail outlets throughout the city. Both the shells and contents of the eggs were cultured using the standard method. Biochemical tests, Salmonella serotyping and PCR were applied to specify and confirm of Salmonella isolates. The overall finding was that 3 samples (0.6%) were contaminated with Salmonella. In two out of 3 contaminated eggs, salmonella was found on shell only; both the shell and content of the other one were contaminated. Prevalence of Salmonella contamination among the barn and free range eggs in Birjand was 0.6%, which is equivalent to approximately 1 in every 165 eggs. This is in accordance with other surveys in Iran (Shiraz, Tehran and Mashhad). Based on the results, to prevent salmonellosis, proper cooking of the eggs is recommended.

One of the most important reasons for students’ evaluation of university teachers and emphasizing on its improvement are to provide academic members with a feedback leading to raise their teaching quality. The current study was conducted to define students’ points of view regarding their tutors in Birjand University of Medical Sciences. In this analytic- descriptive study 280 students of Birjand University of Medical Sciences were surveyed. Their views were assessed through a questionnaire which its content validity was approved after some specialists’ polls and a primary introductory study. Besides, the reliability of the questionnaire was assessed using internal homogeneity and calculating the Koronbach α coefficient. Koronbach α coefficient was found to be 80%. The data were analyzed through SPSS software presenting frequency and then chi-squarer test (P<0.05). From a total of 280 students, 40% believed that the evaluation forms could not evaluate teaching quality to a great extent. 78.2% of them filled out the forms patiently enough and 82.8% thought that the results of evaluation are credited very little. Findings showed that most of the students believed that evaluation results are ignored. On the other hand, little acquaintance of most of the students (80%) with such evaluating centers (Educational Development Center) revealed the need for introductory sessions before evaluations and reminding the importance and applications of the results.

In order to evaluate the effects of limited irrigation on forage of two local populations of Kochia scoparia a field experiment was conducted in Research Field of Center of Excellence for Special Plants at Ferdowsi University of Mashhad during 2007 growing season. The experiment was performed as a split plot design based on complete randomized block arrangement. In the main plots four irrigation levels were applied including complete irrigation, 80%, 60% and 40% of water plant requirements. Two local populations of Kochia including Sabzevar and Borujerd were used in the subplots with 3 replications. The plant characteristics were studied in terms of plant height, branch number, fresh and dry matter weight, green area index (GAI), and leaf and stem dry weight. Results indicated that the different irrigation regimes had a significant effect on all plant characteristics. Maximum forage yield was obtained from complete irrigation with 13.22 t/ha dry matter and 31.81 t/ha fresh materials. Sabzevar's local population represented a better performance on all of the characteristics; however, there was no significant difference among the two populations on dry matter per plant. The interaction effects of limited irrigation and variety showed a significant difference on fresh matter weight, stem dry weight, leaf dry weight, and green area index. The stem dry weight and green area index showed the highest correlation with dry matter and fresh matter weight, respectively. It can be concluded that due to high Kochia’s resistance in the presence of drought, salinity and other desert stresses such as high temperatures this plant has the potential to be used as a forage crop in harsh environmental conditions.