Adaptive Project Monitoring and Control with Variable Reviewing Intervals

This paper presents a managerial project control scheme in which the time between the control points is not fixed but instead is a function of the distance between the planned and the current performance levels. Varying the reviewing interval improves the efficiency of the project monitoring and control process and allows project managers to obtain the required information more quickly. To evaluate the effectiveness of the proposed scheme, a systematic computational experiment is carried out. Besides, a practical case study is given to illustrate the applicability of the proposed scheme. The results reveal the satisfactory performance of the adaptive control scheme

Stress Factors in Dental Students of Babol University

Objective: Dental profession is associated with a high level of stress experienced by clinicians in private practice as well as students and instructors in dental school environment. The purpose of this study was to detect the main stressors in dental students of School of dentistry, Babol University of Medical Sciences in 2011-2012.Methods: In this descriptive, analytical study, data were collected via Dental Environment Stress (DES) questionnaire. Understudy subjects were all dental students in Babol University (n=199) selected by census sampling. Data were analyzed using chi-square and t-tests.Results: Six factors were found to be the main stressors in dental students: 1. More than one exam in the same day (2.76 (0.596)); 2.Insufficient time interval between exams (2.74 (0.581)); 3.Insufficient exam time (2.62 (0.693)); 4.Instructors humiliating students or showing their dissatisfaction of the procedure done by the students in front of patients (2.61 (0.618)); 5.Too many credits offered per semester (2.35 (0.849)) and 6. In appropriate behavior of the staff (2.33 (0.793)). Of all departments in Babol Dental School, departments of Prosthodontics, Radiology and Endodontics caused the highest level of stress and anxiety in students and had statistically significant differences in this regard with other departments.Conclusion: The stressors had greater impacts on female students particularly the fourth year dental students. Attempts must be made to modify the curricula and exam schedules particularly in the most stressful departments to decrease the level of stress in dental students

Evaluation of Gelabar Earth Dam Behavior during Construction and First Watering by the Method of Limited Components and Comparison with Real Amount Resulted by Precise Instruments Data

The increase in pore water pressure in earth-rock fill dams with clay core during construction and first watering can cause the start and progress in hydraulic fracture. Construction costs being high and also the damage caused by dams’ fracture make the necessity of taking care and behavior survey of earth dams, more obvious than anything. According to this, in this research while modeling Gelabar earth dam, pore water pressure, pore water pressure ratio, the amount of total stress and effective stress, arching and lateral soil pressure ratio is measured and has been compared with the amount measured by precise instruments which has the construction capability of Plaxis v8.5 for numerical modeling from two –dimensioned software, has been used. Behavior models used in this analysis, Moher- Coulomb and it is xis v8 hardening. Considering the data of precise instruments installed on Dam’s body and implementing return analysis, real parameters of construction materials was obtained. Evaluation of numerical modeling results and precise instruments can find out an appropriate Dam behavior and consequently, the correct modeling procedure. Also, studies have been indicator of suitable stability and safe position for Gelabar Dam

Congenital Fusion of Maxilla and Mandible: A Case Report

Objective: Congenital fusion of jaws is a rare disorder which is observed in infants and cab ne syndromic and non-syndromic. Limited mouth opening in patients can affect the child growth and cause difficulties in feeding, swallowing and breathing.Case: A In this study, a female infant from Afghanistan, settled in Qom referred to  AlZahra maternity with upper and lower fusion jaws is reported. According to clinical and laboratory examinations, infant had no other disorders except the above said disease, and her jaw fusion was non-syndromic.Conclusion: Treatment of this disease in early stages not only is easier, but also can be effective in terms of child’s growth and feeding; because in most cases TMJ ankylosis occurs due to the lack of mobility and loss of function which leads to difficulties in oral operations

Defluoridation of water via Light Weight Expanded Clay Aggregate (LECA): Adsorbent characterization, competing ions, chemical regeneration, equilibrium and kinetic modeling

International audienceNatural, H2O2 and MgCl2 - modified Light Weight Expanded Clay Aggregate (LECA) were used as fluoride adsorbents. Characterization of LECA and its modified forms was done by infra-red, X-ray diffraction, scanning electron microscope and X-ray fluorescence studies. The specific surface area of HML and MGML was 3.34 and 3.97 times greater than that of NL (11.72 m2/g). Improved chemical composition of Magnesium (as oxide) to 15.6% by 2 M MgCl2 solution was ascertained through XRF results. The fluoride levels were reduced (within the safe limit of WHO: 0.5-1.5 mg/L−1) to 0.39 mg/L, 1.0 mg/L and 0.075 mg/L respectively using natural (NL), H2O2 (HML) and MgCl2 - modified LECA (MGML) at a pH of 6.0 and initial fluoride concentration of 10 g/L for an equilibrium time of 120 min. The sorption capacities of 8.53 mg/g, 17.83 mg/g and 23.86 mg/g were determined for NL, HML and MGML respectively. Validation of kinetic and isotherm models was checked for the present fluoride sorption dynamics. The thermodynamic data revealed that the present fluoride sorption was spontaneous, exothermic and ends up with decrease in randomness. Prediction of fluoride sorption mechanism for onto natural and modified LECA forms was also elucidated. Chloride and sulfate were the highly competing species against fluoride sorption. Regeneration efficiency of the spent LECA materials prompted the ability of MGML even after five cycles of adsorption-regeneration processes

Removal of hardness agents, calcium and magnesium, by natural and alkaline modified pumice stones in single and binary systems

International audienceNatural and alkaline modified pumice stones were used for the adsorption of water hardening cations, Ca2+ and Mg2+. The adsorbents were characterized using XRF, XRD, SEM and FTIR instrumental techniques. At equilibrium time and for 150 mg/L of a given cation, removal efficiencies were 83% and 94% for calcium and 48% and 73% for magnesium for raw and modified pumices, respectively. The optimal pH for raw and modified pumices were found to be 6.0, leading to the removal of 79 and 96% of calcium and 51 and 93% of magnesium by 10 g/L of raw and modified pumice adsorbents, respectively. Maximum adsorption capacities were 57.27 and 62.34 mg/g for Ca2+ and 44.53 and 56.11 mg/g for Mg2+ on the raw and modified pumices, respectively. Ca2+ and Mg2+ adsorption capacities of the pumice adsorbents decreased in the presence of competing cations. Less than 300 min were needed to achieve 99 and 92% desorption of the adsorbed Ca2+ and 100 and 89% of the adsorbed Mg2+ from the natural and modified pumices, respectively. After treating synthetic water solution simulating an actual water stream with the alkali-modified pumice, total hardness of the treated sample met the required standard for drinking water, namely below 300 mg/L of CaCO3 (297.5 mg/L). The studied pumice adsorbents, and especially the treated pumice, can be therefore considered as promising low cost adsorbents, suitable for the removal of hardness ions from drinking water