Prediction of Soil Hydraulic Conductivity at Saturation Using Air Permeability at Any Individual Soil Water Content

Mehdi Rahmati,Mohammad Reza Neyshaboury,Panah Mohammadi 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.12

Several studies aimed at linking hydraulic conductivity at saturation (Kw,s) to air permeability (Ka(θw)) of soil at given water content (θw) since it can be measured more rapidly and nondestructively than Kw,s especially regarding some new in situ technologies for Ka(θw) measurement. Following this, the current research aimed to develop a semi-theoretical relation between Kw,s and Ka(θw) using measured data in 27 soil samples. The Ka(θw) was measured at 12 different θw contents between 1.5 to 1,500 kPa suctions. Applying these measured data, we proposed a semi-theoretical function to predict Kw,s using Ka(θw) as input variable. The results showed that the proposed function was able to predict Kw,s using Ka(θw) at any individual θw content with really high accuracy consisting of R2 = 0.986 and evaluating error (ER) of the 2% between measured and predicted Kw,s. However, the outcomes revealed that Ka(θw) measurement at lower θw contents resulted in greater accuracy for proposed model. The pertinent section of the article applied multivariate linear regression (MLR) to develop pedo-transfer functions (PTFs) to estimate the parameters of the proposed model. The results revealed that the developed PTFs had relatively greater accuracy and reliability showing average determination coefficient (R2) of 0.807 and 0.729 for training and test datasets, respectively. However, more detailed investigation with wide range of soil parameters are needed for more general PTFs development.

Microbial fuel cell for oilfield produced water treatment and reuse: Modelling and process optimization

Majid Mohammadi,Mehdi Sedighi,Rajamohan Natarajan,Sedky Hassan Aly Hassan,Mostafa Ghasemi 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.1

Oilfield produced water is one of the vast amounts of wastewater that pollute the environment and cause serious problems. In this study, the produced water was treated in a microbial fuel cell (MFC), and response surface methodology and central composite design (RSM/CCD) were used as powerful tools to optimize the process. The results of two separate parameters of sulfonated poly ether ether ketone (SPEEK) as well as nanocomposite composition (CNT/Pt) on the chemical oxygen demand (COD) removal and power generation were discussed. The nanocomposite was analyzed using XRD, SEM, and TEM. Moreover, the degree of sulfonation (DS) was measured by NMR. A quadratic model was utilized to forecast the removal of COD and power generation under distinct circumstances. To obtain the maximum COD removal along with maximum power generation, favorable conditions were achieved by statistical and mathematical techniques. The findings proved that MFC could remove 92% of COD and generate 545mW/m2 of power density at optimum conditions of DS=80; and CNT/Pt of 14 wt% CNT- 86 wt% Pt.

A Regionalization Model to Increase Equity of Access to Maternal and Neonatal Care Services in Iran

Zahra Mohammadi Daniali,Mohammad Mehdi Sepehri,Farzad Movahedi Sobhani,Mohammad Heidarzadeh 대한예방의학회 2022 예방의학회지 Vol.55 No.1

Objectives: Access to maternal and neonatal care services (MNCS) is an important goal of health policy in developing countries. In this study, we proposed a 3-level hierarchical location-allocation model to maximize the coverage of MNCS providers in Iran. Methods: First, the necessary criteria for designing an MNCS network were explored. Birth data, including gestational age and birth weight, were collected from the data bank of the Iranian Maternal and Neonatal Network national registry based on 3 service levels (I, II, and III). Vehicular travel times between the points of demand and MNCS providers were considered. Alternative MNCS were mapped in some cities to reduce access difficulties. Results: It was found that 130, 121, and 86 MNCS providers were needed to respond to level I, II, and III demands, respectively, in 373 cities. Service level III was not available in 39 cities within the determined travel time, which led to an increased average travel time of 173 minutes to the nearest MNCS provider. Conclusions: This study revealed inequalities in the distribution of MNCS providers. Management of the distribution of MNCS providers can be used to enhance spatial access to health services and reduce the risk of neonatal mortality and morbidity. This method may provide a sustainable healthcare solution at the policy and decision-making level for regional, or even universal, healthcare networks.

Epidemiological and Clinicopathological Characteristics of Lung Cancer in a Teaching Hospital in Iran

Hajmanoochehri, Fatemeh,Mohammadi, Navid,Zohal, Mohammad Ali,Sodagar, Abolfazl,Ebtehaj, Mehdi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: Lung cancer is one of the most commonly diagnosed cancers and the most frequent cause of cancer-related death worldwide. In Iran, it ranks second and third as the cancer-causing death in men and women, respectively. We carried out this study to find out the demographic, clinical, and histological characteristics and risk factors of lung cancer in a referral tertiary center in Iran. Materials and Methods: A retrospective study was conducted on cases of primary lung cancer based on the results of registered cancer reports of cytological and pathological specimens between March 2001 and March 2012. Demographic variables, clinical manifestations, histology and location of tumors were determined based on the data found in the medical records of each patient. Definite or probable etiologic factors were identified. Data analysis was performed with SPSS version 16 and a p-value ${\leq}0.05$ was considered as significant. Results: A total of 203 patients, with a mean age of 65.7 years (SD=11.2), with primary lung cancer were identified, 81.3% being men. Of the total, 110 cases (54.2%) were living in urban areas. In 53.2% of cases, the site of tumor was on the right side and in 72.9% of cases the lesion was centrally located. The histological types of lung cancer were squamous cell carcinoma (SCC) in 107 cases (52.7%), adenocarcinoma (AC) in 30 cases (14.8%), and small cell carcinoma (SC) in 27 cases (13.3%). Significant correlations between the gender and residence, smoking, and the histological type and location (central or peripheral) of tumor were found. The percentage of smokers was 75.2% in men and 15.8% in women. Conclusions: Smoking was the most important risk factor and squamous cell carcinoma the most common histological type of lung cancer in our study. Male sex and being a smoker was associated with histological types of SCC while being nonsmoker had relationship with adenocarcinoma.

Effect of Cation Distribution on the Structural and Magnetic Properties of Mg Substituted Nanosized Manganese Ferrites

Seyed Taghi Mohammadi,Mehdi Nazirzadeh,Hassan Nanakar 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.1

In the present investigation, A series of Mg-Mn ferrite nanopowders with composition MgxMn1-xFe2O4 (with x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by the co-precipitation method. Thereafter, the obtained powders were pressed separately to form pellets, and sintered at 1250 ℃ for 3 h at air atmosphere. Finally, the samples were characterized by X-ray Diffraction (XRD) technique, Scanning Transmission Electron Microscopy (STEM), Alternating Gradient Force Magnetometer (AGFM) and Curie temperature measuring instrument. The lattice constant and distribution of cation in the tetrahedral and octahedral sites have been deduced through XRD data analysis. The XRD pattern confirmed the existence of single phase of cubic spinel crystal structure with the lattice parameter ranging from 8.49 Å (for MnFe2O4) to 8.35 Å (for MgFe2O4). This behavior was attributed to the ionic radii. STEM micrographs exhibit that the particles are spherically shaped and agglomerated with particle size ranging 50–90 nm quite consistent with particle size obtained from XRD data. The average crystallite size was 70nm. Magnetization decreases with increasing Mg concentration except for x = 0.2, where it shows increasing trend. Curie temperature measurements exhibit increasing trend with increase in magnesium content. The variation of the saturation magnetization and Curie temperature with increasing concentration of the Mg2+ ions can be explained on the basis of cation distribution, strengthening A–B interaction and Neel's two sub-lattice.

High Rate of Advanced Colorectal Polyps in a 10-Year-Long Retrospective Study in Qazvin, Iran

Hajmanoochehri, Fatemeh,Mohammadi, Navid,Rasoli, Bashir,Ebtehaj, Mehdi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Background: Polyps are common lesions in the gastrointestinal (GI) tract. Colon cancer is mostly a result of progression from polyps. The present study aimed to evaluate demographic, clinical, and histological characteristics of colorectal polyps in Iran, particularly neoplastic and advanced types. Materials and Methods: Over a period of 10 years, specimens of all colorectal polyps obtained from colonoscopy were studied. The variables subjected to statistical analysis were age, sex, and the chief clinical complaint of the patients who underwent colonoscopy, their motivation, and the site, size, and histological types of detected polyps. The level of significance was set at p value <0.05. Results: Data were obtained from a total of 352 patients. No difference was seen between male and female patients regarding histological types. Only in nine patients was screening the reason for colonoscopy. Almost two-thirds (66.2%) of the polyps were neoplastic. Familial polyposis syndrome and inflammatory bowel disease were seen in 4.3% and 3.0% of the patients with neoplastic polyps, respectively. Sites of polyps were the sigmoid, rectum, and descending colon in 40.1%, 34.5%, and 17% of the cases, respectively. The advanced type made up 58.8% of neoplastic polyps. Only 3.6% of the patients undergoing colonoscopy in the study period had biopsied polyps. Discussion: No difference was observed between male and female patients in terms of overall incidence of polyps, histological and anatomical profiles, and mean age distribution. Anatomical and histological profiles agreed with the studies performed in areas with a low risk of colon cancer. The findings show that colonoscopy was not performed when it was necessary. A meaningful increase in the number polyp biopsy cases and a corresponding decrease in polyp size in the last few years of the study can be associated with the presence of more GI specialist clinicians in hospital centers, and this holds out much hope for the further improvement of the situation in the future.

Validity Assessment of the Persian Version of the Nordic Safety Climate Questionnaire (NOSACQ-50): A Case Study in a Steel Company

Yadolah Yousefi,Mehdi Jahangiri,Alireza Choobineh,Hamidreza Tabatabaei,Sareh Keshavarzi,Ali Shams,Younes Mohammadi 한국산업안전보건공단 산업안전보건연구원 2016 Safety and health at work Vol.7 No.4

Background: The Nordic Safety Climate Questionnaire-50 (NOSACQ-50) was developed by a team of Nordic occupational safety researchers based on safety climate and psychological theories. The aim of this study was to develop and validate the Persian version of NOSACQ-50 and assess the score of safety climate on a group of workers in a steel company in Iran. Methods: The Persian version of NOSACQ-50 was distributed among 661 employees of a steel company in Qazvin Province (Iran). Exploratory factor analysis (EFA) and confirmatory factor analysis were used to determine the dimensions of the questionnaire. The reliability of the questionnaire was assessed using Cronbach α coefficient. Pearson correlation test was applied to investigate the correlation between different dimensions. Results: The results of EFA showed that the Persian version of NOSACQ-50 consisted of six dimensions. The Cronbach α coefficient of the questionnaire was 0.94. The mean score of safety climate in all dimensions was 2.89 (standard deviation 0.60). Conclusion: The Persian version of NOSACQ-50 had a satisfactory validity for measuring safety climate in the studied Iranian population.

Estimation of Soil -Water Characteristic Curve Using One-Point Measurement

Ali Asghar Zolfaghari,Mehdi Shorafa,Mohammad Hossein Mohammadi,Manouchehr Gorji 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Scoring of Tenders in Construction Projects Using Group Method of Data Handling

Masoud Nouri Mehrabani,Emadaldin Mohammadi Golafshani,Mehdi Ravanshadnia 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.7

In a competitive construction environment, contractors are often faced with a large number of tenders that compel them to make the best decision in a limited time. In this paper, a decision support system (DSS) based on group method of data handling model (GMDH) was developed for the scoring of tenders (STs). Based on a comprehensive study of the existing literature and experts’ opinions, seven criteria were extracted, namely client, contract, company, consulting engineers, project status/situation, risk, and economic criteria as the inputs of the system. To develop the DSS, the data from 135 tenders were collected from the previous tenders of a private construction contractor. The results illustrate that the proposed model, with a negligible error, is reliable in ST. Moreover, the proposed model specifies the score of new tenders, and decision-makers (DMs) can easily make their decisions in prioritizing and evaluating new tenders. Furthermore, a sensitivity analysis was performed to address the importance of the criteria, and it was concluded that the contract related criterion is the most important principle to the contractor. Eventually, a graphical user interface was designed in a user-friendly environment which allows the decision-makers to visualize the ST.

Effects of Rewashing Pistachio using a Floating Tank Process on Reducing Spore Density of Aflatoxin Producing Fungus

Hossein Hokmabadi,Behrouz Gheibi,Mehdi Mohammadi Moghadam,Faranak Hadavi 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-