Estimation and assessment of cost and revenue for solid waste management subsystems in Tehran city using mathematical functions

Background and Aims: The municipality of Tehran has recently attempted to implement the integrated waste management system (IWMS) with the approach of minimizing environmental emissions, the lowest cost and the maximum utilization of existing potential. The present study set out with the aim of assessingthe fixed and variable investment costs along with estimating the cost functions of its subsystems.Materials and Methods: Recorded data from September to October in 2014- 2015 were used, making arrangements well in advance. The annual waste input to each subsystems of IWMS was firstly divided into 0 to twice of input ratio. The amount of fixed and variable investment costs along with future costs were then determined considering experts’ opinions. Finally, MATLAB software version 7.1 was used in order to coding, estimating cost functions, and determining the correlation coefficient (R2) between the input and cost values.Results: The results showed that transportation subsystem allocated the maximum amount of costs (43%). Processing (23%), anaerobic digestion (12%), aerobic digestion (9%), landfilling (7%), and incineration (6%) were ranked in the next positions, respectively. Furthermore, using actual cost data based on existing capacity as well as peer reviewed experts’ data with theoretical capacity indicated that all subsystems had economic scale with high correlation coefficients.Conclusion: It is concluded that directing the waste flow from burial site to other waste processing technologies such as separation of recyclable materials, aerobic digestion, anaerobic digestion, and incineration would result in a significant reduction in the total amount of costs.Keywords: Municipal solid waste, Waste management, Mathematical Functions, Operating cost, Unit costFor downloading the full text please click here

Evaluation of minimum cost and greenhouse gas emissions from municipal solid waste processing and disposal centers using NSGA II algorithm

Background and Aims: Assessment of the stability of an integrated solid waste management system (ISWMS)necessitates analysis of effective criteria. The present study was therefore designed to provide a simple mathematical model to optimize ISWMS aiming at minimizing the cost and emission of greenhouse gases (GHG).Materials and Methods: In order to make use of data recorded during September to October (2014- 2015), it was necessary to make arrangements well in advance with the directors of Waste Management in Tehran. The proposed model was applied and consequently analyzed for allocation of eleven MSW components (including: paper, cardboard, plastic, nylon, metal, glass, PET, wet waste, bread, mixed recyclables and other wastes) into three sub-systems of MSW management (i.e., processing and separation, anaerobic digestion and land filling) at Abali processing and disposal center using NSGA II algorithm.Results: The results of this study indicate that the costs and emissions of GHG would be significantly reduced by increased separation rate in a municipal ISWMS. Furthermore, the identified optimum condition was 100 percent separation and processing with 486 USD (revenue) and 2438 Kg reduced CO2 (avoided emissions) representing a substantial improvement in the ascending trend rate of disposal separation.Conclusion: It seems necessary to increase daily waste entrance into Abali complex and complement the proposed system with other sub-systems concerning economic and environmental issues in order to enhance the technical feasibility of establishing such a system. On the other hand, given that transport and landfill sub-systems don’t have any positive economic and environmental issues, the flow and rate of waste allocation to these sub-systems should be followed in a carefully planned and exact way.Keywords: NSGA II algorithm, Municipal Solid Waste, Greenhouse Gases, Mathematical mode

Optimization Model for Maintenance Planning of Loading Equipment in Open Pit Mines

Maintenance plays a significant role in operating costs in the mining industry. Improving this matter controls maintenance costs and enhances productivity and production effectively. Shovels are one of the most widely used loading machines in non-continuous activities. Thus, evaluating and optimizing their availability is one of the essential solutions to achieving high productivity and cost reduction. This paper presents a mathematical programming model to maximize availability and minimize the total expected costs. We programmed the proposed nonlinear planning model using the Symbiotic Organisms Search (SOS) meta-heuristic algorithm in Matlab software. It determines the optimal maintenance intervals for different parts of the shovel. The maintenance benefit analysis approach selects various maintenance activities in optimal maintenance intervals. The model is implemented in a practical case study, Chadormalu Iron Mine, to evaluate its performance. The failure distribution matches the Weibull distribution function. The computational results show the efficiency of the presented approach

The effect of Syrian mesquite (Prosopis farcta) seed extract on thioacetamide-induced oxidative stress in rats

Background: This experimental study aimed at investigating the effect of Prosopis farcta seeds hydro-alcoholic extract on thioacetamide-induced oxidative stress in rats. Materials and Methods: In this study, 30 adult male rats were randomly divided into three groups: healthy control, positive control, and P. farcta- treated group received thioacetamide. The healthy control rats received normal saline orally. The positive control rats received thioacetamide (50 mg/kg IP) for three times at one-day interval (oxidative stress induction). The P. farcta seed extract (100 mg/kg) was administered orally for 21 days. At the end of the experiment, blood samples were taken from the rats' heart to separate serum and the serum catalase (CAT) and superoxide dismutase (SOD) activities were determined. After euthanasia, liver and kidney were separated to determine malondialdehyde (MDA) levels. Results: The activities of CAT and SOD were significantly lower in the thioacetamide- intoxicated group compared to those in the healthy control group (P<0.001). The treatment with P. farcta seed extract significantly increased the activities of these enzymes compared to the positive control group (P<0.001). Moreover, after three weeks of oral treatment, the P. farcta seed extract significantly reduced the liver MDA concentrations compared with the positive control rats (P<0.05). Conclusion: It can be concluded that P. farcta seed hydro-alcoholic extract can protect against thioacetamide-induced oxidative stress

A Prospective Cohort Study of Cutaneous Leishmaniasis Risk and Opium Addiction in South Eastern Iran

Opium addiction and cutaneous leishmaniasis (CL) are endemic in different parts of Iran, particularly in Bam, where a massive earthquake occurred. This study was designed to compare the incidence rate and severity of CL cases among opium addicted and non-addicted individuals in south-eastern Iran. This study was carried out as a prospective cohort by active house-to-house visits of 1,481 habitants in Bam. CL cases were confirmed by smear and identification of Leishmania species was performed using nested-PCR. The data was analyzed by x2 and t-tests, using SPSS software and also KaplanMeier survival curve and long-rank test in Stata 11.2 and P,0.05 was considered as significant. A total of 904 individuals consisting of 226 opium addicted and 678 non-addicted individuals were followed-up for a period of seven years. The two cohorts were similar in terms of age, sex and place of residency. A similar pattern of incidence was observed among the two cohort groups. In contrast, the severity of CL in terms of the number, duration and the size of the lesions in opium addicted individuals was significantly (P,0.001) higher than non-opium addicted individuals. In conclusion, the present findings indicate that there is no relationship between the incidence of CL and opium addiction

A preliminary survey of Autism knowledge and attitude among health care workers and pediatricians in Tehran, Iran

Objective: Autism spectrum disease (ASD) is not a common diagnosis for children presenting with neurodevelopmental delay before 36months in Iran. Although recent years have witnessed improvements in diagnosis of pediatrics psychological disorders but the role of referral system starting with health care workers (HCW) is not clear.Methods: Pediatricians were randomly selected from four teaching hospital of Tehran University of Medical Sciences Iran. HCW were randomly selected from 3 urban health care centers in Tehran, Iran. DSM-IV TR criteria for ASD was used to assess knowledge. Participants were asked to rate sixteen statements on beliefs about autism to assess attitude. Results: one hundred and twenty two pediatricians and ninety HCWs with mean ± SD age of 36±4.7   years and 76.4% being female recruited. Pediatricians had significantly higher encounter with autistic patients (18% Vs 10%, p value=0.06) and parents of autistic child (17% Vs 12%, p value=0.07). But generally 209 participants (98.6%) declared that they are familiar with autism. There was no statistically significant difference between study groups in rating DSM-IV TR criteria for ASD as “necessary for diagnosis”. Age, gender and working experience, did not differ pediatricians or HCW answers (all p values > 0.05). Among HCW participants, higher educational level was associated with higher disagreement about “autistic children is schizophrenic”(p value=0.01). Also HCW with higher working experience had higher agreement rate with “autistic children needs special education” statement (p value= 0.04).Conclusion: There are still misconceptions about ASD regarding developmental, cognitive and emotional features in both HCW and pediatricians needed to be educated through national program.

Effects of diabetes on myocardial capillary density and serum angiogenesis biomarkers in male rats

INTRODUCTION: Cardiovascular disease is one of the main causes of mortality and morbidity in diabetic patients. This study evaluated the effects of diabetes on myocardial capillary density and several serum angiogenic factors including nitric oxide, vascular endothelial growth factor, and soluble vascular endothelial growth factor receptors. METHODS: Twelve male rats were divided into two groups: control and diabetic (n = 6 each). Diabetes was induced with a single dose of streptozotocin (50 mg/kg). After 21 days, capillary density in the myocardial tissue was evaluated using immunohistochemical staining and is reported as capillaries per mm². Blood samples were collected before and after the induction of diabetes. RESULTS: In the diabetic group, serum nitric oxide and soluble vascular endothelial growth factor receptor 2 concentrations were lower than the levels in the control group, while the level of soluble vascular endothelial growth factor receptor 1 was significantly higher. There was no significant change in the serum vascular endothelial growth factor concentration between the diabetic and control groups; however, the ratio of vascular endothelial growth factor to vascular endothelial growth factor receptor 1 was significantly lower in the diabetic animals. The myocardial capillary density was also lower in the diabetic group compared with the control group (1549 ± 161 vs. 2156 ± 202/mm², respectively). CONCLUSION: Reduced serum nitric oxide and vascular endothelial growth factor receptor 2 levels, increased serum vascular endothelial growth factor receptor 1 levels and a lower vascular endothelial growth factor to vascular endothelial growth factor receptor 1 ratio may be responsible for the decreased myocardial capillary density in diabetic rats

Inductive and Deductive: Ambiguous Labels in Qualitative Content Analysis

The propounded dualism in Content Analysis as quantitative and qualitative approaches is widely supported and justified in nursing literature. Nevertheless, another sort of dualism is proposed for Qualitative Content Analysis, suggesting the adoption of inductive and/or deductive approaches in the process of qualitative data analysis. These approaches have been referred and labelled as inductive or conventional ; and deductive or directed content analysis in the literature. Authors argue that these labels could be fallacious, and may lead to ambiguity; as in effect, both approaches are employed with different dominancy during the process of any Qualitative Content Analysis. Thus, authors suggest more expressive, comprehensive, yet simple labels for this method of qualitative data analysis

Endoscopic Surgery for Third Ventricular Colloid Cysts in the Absence of Hydrocephalus- a feasibility study

Purpose: The aim of this study was to investigate the feasibility and effectiveness of endoscopic neurosurgery for patients with third ventricular colloid cysts without ventriculomegaly.Methods: Seventy-one patients with third ventricular colloid cysts were identified and recruited to this study. Eighteen of these patients did not have concomitant hydrocephalus and underwent primary endoscopic surgery for cyst resection. The surgical technique, the success rate, and patients’ outcome were assessed and compared with 53 hydrocephalic patients who underwent similar procedures.Results: The ventricular compartments were successfully cannulated and gross total resectin of the colloid cysts was achieved in all patients. There were no operative complications related to the endoscopic procedure. Two patients required subsequent intervention for hydrocephalus. The success rate for endoscopic surgery in non-hydrocephalic patients was similar to its value in patients with hydrocephalus.Conclusion: Endoscopic resection of third ventricular colloid cyst in patients without hydrocephalus seems to be feasible, effective and not contraindicated