20 research outputs found
Impact of Arterial Characteristics on the Operational Performance of Traffic on Urban Arterials Near Diamond Interchanges
Urban arterials near freeway interchanges are vital segments of road infrastructure. While freeways have high mobility and low access, urban arterials have medium mobility and medium access. Designing facilities that can efficiently connect these two types of roads is complex. There is an increasing need in the profession to have an in-depth understanding of the operational performance of urban arterials, while no clear and straightforward recommendations exist to enumerate the impact of various design and operational elements on the operational performance of traffic on urban arterials.
This dissertation suggests a step-by-step methodology to (a) comprehensively study traffic flow on urban arterials located in the vicinity of diamond interchanges, (b) quantify the impact of the urban street characteristics on lane changing, and subsequently, (c) study how lane change behavior impacts travel time. This research studied two dependent variables, and, as a result, two final statistical models were built to demonstrate the relationship between the contributing factors and the dependent variables: travel time and lane changing.
PTV-VISSIM software was the main simulation tool used in this study. Each micro-simulation model was validated and calibrated for base conditions for each output: travel time (TT) and the number of lane changes (NLC). The author used factorial simulation and a hashing method to create all possible simulations by using the Python programming language. The final outputs were filtered to remove any redundant scenarios. After compiling inputs and outputs in a filtered and adjusted database, the author used the R programming language to conduct linear regression analyses. The results show that the main contributing factors to the number of lane changes aside from the through, left, and right turning volumes are the number of driveways, distance of the right turning lane to the upstream intersection, and the number of median openings. The results indicated that adding each driveway contributed to 54 more lane changes, while each median opening added 79 more lane changes per hour. Also, placing the start of the right turning lane closer to the first signalized intersection lead to fewer lane changes on the segment.
The number of lane changes, the density of the driveways, segment length, and being located upstream to the freeway on-ramp contributed to higher travel times. The findings of this research provide designers and urban planners a deeper insight into the impact of design attributes on the operational performance of urban arterials near interchanges
Sjuksköterskans möte med kvinnliga muslimska patienter
The number of people with another culture is increasing in Sweden. This change in society brings consequences in health care that has not any methods to manage. The Muslim woman’s meeting with the health care is one of those areas. The aim with this study was to describe the nurses meeting with female Muslim patient. The study carried out as a literature study and the results which based on 9 articles showed the lack of knowledge about culture and religion among health care staff. The authors further believed that to achieve an adequate result with meeting between staff and patient requires knowledge about different culture and religion. The study shows furthermore a necessity for nurses training individually to create instinct in how their own cultural opinion affects the nurse in her/his profession. The patients felt like nurses had a stereotype to doing their job and got very difficult to satisfy patients with the needs. In view of the circumstances it notifies proposals to improvement in the existing health care through curses and seminars about culture and religion but even concrete information about Islam and Muslim female patient’s needed in an institutional care. Madeleine Leininger’s theory of culture care was used as the conceptual framework and support for the study
Impact of Arterial Characteristics on the Operational Performance of Traffic on Urban Arterials Near Diamond Interchanges
Urban arterials near freeway interchanges are vital segments of road infrastructure. While freeways have high mobility and low access, urban arterials have medium mobility and medium access. Designing facilities that can efficiently connect these two types of roads is complex. There is an increasing need in the profession to have an in-depth understanding of the operational performance of urban arterials, while no clear and straightforward recommendations exist to enumerate the impact of various design and operational elements on the operational performance of traffic on urban arterials.
This dissertation suggests a step-by-step methodology to (a) comprehensively study traffic flow on urban arterials located in the vicinity of diamond interchanges, (b) quantify the impact of the urban street characteristics on lane changing, and subsequently, (c) study how lane change behavior impacts travel time. This research studied two dependent variables, and, as a result, two final statistical models were built to demonstrate the relationship between the contributing factors and the dependent variables: travel time and lane changing.
PTV-VISSIM software was the main simulation tool used in this study. Each micro-simulation model was validated and calibrated for base conditions for each output: travel time (TT) and the number of lane changes (NLC). The author used factorial simulation and a hashing method to create all possible simulations by using the Python programming language. The final outputs were filtered to remove any redundant scenarios. After compiling inputs and outputs in a filtered and adjusted database, the author used the R programming language to conduct linear regression analyses. The results show that the main contributing factors to the number of lane changes aside from the through, left, and right turning volumes are the number of driveways, distance of the right turning lane to the upstream intersection, and the number of median openings. The results indicated that adding each driveway contributed to 54 more lane changes, while each median opening added 79 more lane changes per hour. Also, placing the start of the right turning lane closer to the first signalized intersection lead to fewer lane changes on the segment.
The number of lane changes, the density of the driveways, segment length, and being located upstream to the freeway on-ramp contributed to higher travel times. The findings of this research provide designers and urban planners a deeper insight into the impact of design attributes on the operational performance of urban arterials near interchanges
Relationship between Plasma Concentrations of Maternal Zinc during Pregnancy and the Risk for Orofacial Cleft
Aim: Recent studies have suggested the occurrence of a variety of abnormalities including oral clefts following the deficiency of nutritional elements. The present study aimed to address the association between plasma concentrations of maternal zinc and the risk of an infant being born with an orofacial cleft. Materials and Methods: In this case-control study conducted in Hamadan, Iran, 2015, 48 mothers of children with an isolated cleft lip with or without cleft palate and 48 control mothers of children with no congenital malformations were recruited. The concentration of zinc in the whole blood was measured using flame atomic absorption spectrometry method. Data were analyzed by the use of descriptive and analytical statistics in SPSS version 16. Results and Discussion: Plasma level of zinc in a group with orofacial clefts was 16.87 +/- 8.17 mu mol/L, and in the control group was 19.28 +/- 8.83 that was statistically similar between the groups (t = -1.329, P = 0.187). T-test showed that the two groups did not have a significant difference in zinc level. The odds ratio (OR) for the case and control group was 1.6, which indicates there was no significant difference in zinc deficiency between the two groups (OR = 1.66, 95 confidence interval = 0.61-4.54, P = 0.426). Conclusion: Despite lower zinc plasma levels in women of the case group, the difference in concentration of this element was not statistically significant between the two groups. In general, there is no definitive conclusion on whether the deficiency of nutritional elements during pregnancy is the cause of malformations or not, and it is still necessary to further studies
Relationship between dental plaque formation and salivary cortisol level in pregnant women
Purpose: Understanding how increased level of salivary cortisol contributes to the development of dental biofilm during pregnancy can help inthe prevention of dental caries and periodontal diseases. This study aims to evaluate the relationship between salivary cortisol level and dental biofilm formation in pregnant women. Patients and methods: This descriptive-analytic study was conducted in Hamadan, Iran in 2011. Forty consecutive pregnant women with no history of abortion, stillbirth, or any known physical or psychological disorders at weeks 25 and 33 of gestation were included. Salivary samples were collected for measurement of cortisol levels by Enzyme Linked Immunoabsorbent Assay (ELISA) method. The amount and extension of dental biofilms were determined by using a disclosing agent. Data were analyzed using descriptive and analytical statistics in SPSS version 16. Results: The mean levels of salivary cortisol at weeks 25 and 33 of gestation were respectively, 2.45 +/- 1.56 mug/dl and 5.24 +/- 4.07 mug/dl which demonstrates a significant difference (P<0.001). Evaluation of dental biofilm at two time intervals revealed a significant increase in amount of dental biofilm at week 33 of gestational period (34.65 +/- 10.9 vs. 42.45 +/- 12.35, P<0.001). Elevated levels of dental biofilm were significantly correlated with salivary cortisol levels at week 33 (r=0.494, P=0.001),however, it was not significant at week 25 of gestation (r=0.148, P=0.361). Conclusion: The findings suggested that increased levels of salivary cortisol can predict dental biofilm formation and accumulation in pregnant women in the last weeks of gestation
Investigating the relationship between DMFT index of pregnant women and neonates’ low birth weight in Hamadan in 2016
Introduction: Low birth weight (LBW), defined as a weight less than 2500 g, is strongly associated with a neonatal mortality. Many studies show a positive association between periodontal disease of pregnant mothers and LBW, but few studies have been conducted on the relationship between the dental decays and the LBW. Thus, due to the lack of information in this field, the present study was conducted to evaluate the relationship between DMFT index of the pregnant women in Hamadan and neonates’ LBW. Materials and Methods: This case-control study was conducted on the pregnant women of Hamadan in 2016. The experimental group consisted of 114 pregnant mothers who had normal vaginal delivery and their neonates’ birth weight was less than 2500 g. The control group consisted of 147 pregnant mothers who had normal vaginal delivery and their neonates’ birth weight was over 2500 g. The data were collected based on an interview and examination. The data collection tool was a questionnaire consisting of two sections, including demographic characteristics and dental information. The data were analyzed using descriptive and analytical statistics with SPSS version16 software and P <0.05 was considered as the significance level. Results: The results showed that the mothers in the experimental and control groups were significantly different in terms of DMFT index (P=0.003). The mean of DMFT index in the experimental and control groups were 13.03 and 10.66, respectively. This difference was statistically significant. The correlation coefficient revealed no significant relationship between DMFT index and the neonatal weight in the control group (p=0.532). Conclusion: According to the results of the present study, there is a positive relationship between the dental decays of the pregnant women and the neonates’ LBW. To prevent neonates’ LBW, the public health providers and mass media should provide essential oral hygiene promoting and maintaining programs for pregnant women. Also, due to limited number of studies in this area, further studies in different populations and races seem to be necessary. © 2020, Venezuelan Society of Pharmacology and Clinical and Therapeutic Pharmacology. All rights reserved
Taurodontism: A case report of successful treatment of root and crown
Taurodontism is a rare dental anomaly in which the involved tooth has enlarged and elongated body and pulp chamber with apical displacement of the pulpal floor. Endodontic treatment of these teeth is challenging because it requires identifying the number of root canals. A case of bilateral involvement of maxillary first molar teeth is presented. Endodontic treatment of the right maxillary first molar with taurodontism was indicated due to irreversible pulpitis. In this article, we described the procedure of root canal therapy for this case
Comparison the Effects of Different Root Canal Irrigants on the Retention of Quarts Fiber Posts Cemented by Resin Cement
Introduction: Root canal irrigants could change the structure of root dentin and affect the posts retention the purpose of this study was to compare the effects of three different endodontic irrigants on the retention of quarts fiber posts cemented by different resin cements. Materials & Methods: In this in-vitro study, 10 mm long post spaces were prepared in root canals of 120 premolars after endodontic therapy and cutting the crowns at the cementoenamel junction. The teeth were randomly divided into four equal groups based on the irrigants as follows: distilled water, 2% chlorhexidine, 0.25% iodine and 1% NaOCl. Quarts fiber posts were cemented by Panavia F2. Samples were stored at 370c and humidity of 100% for one week. After thermocycling, the retention of fiber posts were measured by tensile test and modes of failure were reported. Data were analyzed by One-Way ANOVA, Tukey and Fisher's exact tests.Results: The mean and standard deviation of the posts retention were 367.08±63.07, 377.59±72.02, 363.11±68.53 and 342.89±74.94 for distilled water, chlorhexidine 2%, iodine 0.25% and sodium hypochlorite, respectively. One-way ANOVA showed that there was a significant difference among the groups (P<0.001). The results of Tukey test showed that posts retention was significantly higher after rinsing by chlorhexidine (P<0.01)Conclusion: According to the results of this study, chlorhexidine rinse had a favorable effect on retention of posts cemented by resin cement
An Enhanced Python-Based Open-Source Particle Image Velocimetry Software for Use with Central Processing Units
Particle Image Velocimetry (PIV) is a widely used experimental technique for measuring flow. In recent years, open-source PIV software has become more popular as it offers researchers and practitioners enhanced computational capabilities. Software development for graphical processing unit (GPU) architectures requires careful algorithm design and data structure selection for optimal performance. PIV software, optimized for central processing units (CPUs), offer an alternative to specialized GPU software. In the present work, an improved algorithm for the OpenPIV–Python software (Version 0.25.1, OpenPIV, Tel Aviv-Yafo, Israel) is presented and implemented under a traditional CPU framework. The Python language was selected due to its versatility and widespread adoption. The algorithm was also tested on a supercomputing cluster, a workstation, and Google Colaboratory during the development phase. Using a known velocity field, the algorithm precisely captured the time-average flow, momentary velocity fields, and vortices
Effect of Accelerated Artificial Aging on Translucency of Methacrylate and Silorane-Based Composite Resins
Objectives: Composite restorations must have tooth-like optical properties namely color and translucency and maintain them for a long time. This study aimed to compare the effect of accelerated artificial aging (AAA) on the translucency of three methacrylate-based composites (Filtek Z250, Filtek Z250XT and Filtek Z350XT) and one silorane-based composite resin (Filtek P90).
Materials and Methods: For this in vitro study, 56 composite discs were fabricated (n=14 for each group). Using scanning spectrophotometer, CIE L*a*b* parameters and translucency of each specimen were measured at 24 hours and after AAA for 384 hours. Data were analyzed using one-way ANOVA, Tukey’s test and paired t-test at P=0.05 level of significance.
Results: The mean (±standard deviation) translucency parameter for Filtek Z250, Filtek Z250XT, Filtek Z350XT and Filtek P90 was 5.67±0.64, 4.59±0.77, 7.87±0.82 and 4.21±0.71 before AAA and 4.25±0.615, 3.53±0.73, 5.94±0.57 and 4.12±0.54 after AAA, respectively. After aging, the translucency of methacrylate-based composites decreased significantly (P0.05).
Conclusions: The AAA significantly decreased the translucency of methacrylate-based composites (Filtek Z250, Filtek Z250XT and Filtek Z350XT) but no change occurred in the translucency of Filtek P90 silorane-based composite.
Keywords: Composite Resins; Silorane Resins; Methacrylate