Determination of cadmium, nickel, lead and vanadium concentrations in white Indian prawn sold in Shiraz town

زمینه و هدف: با گسترش آلاینده ها در محیط زیست و وابستگی انسان به محیط برای تأمین مواد غذایی و سایر نیازها، بررسی در مورد انواع آلودگی به خصوص آب ها و سایر آبزیان حائز اهمیت می باشد. هدف از این مطالعه بررسی و تعیین میزان غلظت فلزات سنگین کادمیوم (Cd)، نیکل (Ni)، سرب (Pb) و وانادیوم (V) در عضلات و پوست میگوی سفید هندی (Fenneropenaeus indicus) خوراکی در شهرستان شیراز بوده است. روش بررسی: در این مطالعه مقطعی در پاییز سال 1390 با مراجعه به بازار عمده عرضه آبزیان تعداد 120 نمونه میگو به صورت تصادفی از سطح شهر شیراز تهیه شد. آماده سازی و آنالیز نمونه ها مطابق با دستورالعمل های توصیه شده صورت پذیرفته و میزان فلزات سنگین با دستگاه نشر اتمی (ICP) مدل Varian V10-ES تعیین و با مقادیر توصیه شده استاندارهای جهانی WHO و FAO مورد مقایسه قرار گرفت. یافته ها: میانگین غلظت عناصر کادمیوم، نیکل، سرب و وانادیوم در نمونه های مورد مطالعه در بافت عضله به ترتیب برابر با 45/0±08/1، 25/1±62/8، 1/2±63/1 و 93/0±61/0 میلی گرم در کیلوگرم و در پوست 38/0±28/1، 53/1±61/7، 6/4±15/7 و 45/0±4/1 میلی گرم در کیلوگرم وزن بدن اندازه گیری گردید. میزان فلزات سنگین کادمیوم، سرب و وانادیوم در پوست میگو و میزان نیکل در عضله میگو در مقایسه با یکدیگر بیشتر بود (05/0

Gas mixing enhancement in minichannels using a rotationally oscillatory circular cylinder

Oscillating structures and actuators can induce flow kinematics that enhances mixing. This approach is specifically effective for mixing enhancement in meso-scale channels, where the flow kinematics can be actively controlled using micro-electro-mechanical-systems (MEMS). In this paper, numerical results for mixing of two incompressible ideal gas (Schmidt number of 1.0) streams through a 2 D mi nichannel via a rotationally oscillating circular cylinder are presented and discussed. Simulations are performed for blockage ratio of D/H=1/3 and Reynolds number of 100 and oscillation amplitudes of , and for subharmonic (F 1) regimes. Numerical results indicate that mixing performance is improved by about 70% compare to the plane channel at oscillation amplitude of and excitation frequency of 25% higher than the natural frequency of vortex shedding of a stationary cylinder. It is shown that the mixing efficiency is increased by increasing of amplitude in all the cases except at very low excitation frequencies. This study also shows that when the excitation frequency is equal to the vortex shedding frequency the maximum power is required for mixing of two gases

Gas mixing enhancement in minichannels using a rotationally oscillatory circular cylinder

Oscillating structures and actuators can induce flow kinematics that enhances mixing. This approach is specifically effective for mixing enhancement in meso-scale channels, where the flow kinematics can be actively controlled using micro-electro-mechanical-systems (MEMS). In this paper, numerical results for mixing of two incompressible ideal gas (Schmidt number of 1.0) streams through a 2 D mi nichannel via a rotationally oscillating circular cylinder are presented and discussed. Simulations are performed for blockage ratio of D/H=1/3 and Reynolds number of 100 and oscillation amplitudes of , and for subharmonic (F 1) regimes. Numerical results indicate that mixing performance is improved by about 70% compare to the plane channel at oscillation amplitude of and excitation frequency of 25% higher than the natural frequency of vortex shedding of a stationary cylinder. It is shown that the mixing efficiency is increased by increasing of amplitude in all the cases except at very low excitation frequencies. This study also shows that when the excitation frequency is equal to the vortex shedding frequency the maximum power is required for mixing of two gases

Heat Transfer Enhancement in a Straight Channel via a Rotationally Oscillating Adiabatic Cylinder

Heat convection from the uniformly heated walls of a straight channel in presence of a rotationally oscillating cylinder (ROC) is simulated at Re = 100. Heat transfer enhancement due to vortex shedding from the ROC is investigated. Systematic studies are performed to explore the rotation angle and frequency influences on heat transfer by varying the latter in range of the lock-in regime and the former from 0 to 2 π/3. All simulation results are based on the numerical solutions of two-dimensional, unsteady, incompressible Navier-Stokes and energy equations using an h/p type finite element algorithm. Considering time periodicity of the resulting flow and temperature fields, time averaged wall Nusselt number is reported to quantify the heat transfer enhancement for Pr = 0.1, 1.0, 5.0 and 10.0 fluids. Performance analyses of the ROC device based on its total power consumption and heat transfer enhancement are also presented

Investigation on wastewater quality of food industry of Hamedan Province (Case study: Khosh Noosh Company)

Food industries are among the main national industries allocating a significant contribution in terms of total production, water consumption, and effluent generation. Khosh Noosh company is one of the main food industry in Hamedan City that its effluent releases into the Jorghan River after treatment and finally IS USED for irrigation of agricultural lands. The aim of this study was to assess the company's effluent quality and its comparison with the standards of U.S. Environmental Protection Agency, World Health Organization and the National Department of Environment. During this study, a station from the exit of the company and the entrance to the Jorghan River was selected and parameters of pH, TSS, TDS, COD, BOD5, total coliform and fecal coliform were evaluated. The study found that there is a significant relationship between pH and the standard of National Department of Environment at 95% confidential level. However, no significant relationship was stablished between other parameters and this standard. With a confidence level of 95%, there was a significant difference between TDS and the World Health Organization and the U.S. Environmental Protection Agency standards. The correlation between chemical and biological factors in Khosh Noosh Company indicated that there is a significant relationship only between BOD5 to COD and pH and also between pH and total coliforms with 95% confidence level. While no significant relationship exists between other factors

Effect of cylinder proximity to the wall on channel flow heat transfer enhancement

Heat-transfer enhancement in a uniformly heated slot mini-channel due to vortices shed from an adiabatic circular cylinder is numerically investigated. The effects of gap spacing between the cylinder and bottom wall on wall heat transfer and pressure drop are systemically studied. Numerical simulations are performed at Re=100, 0.1⩽Pr⩽10 and a blockage ratio of D/H=1/3. Results within the thermally developing flow region show heat transfer augmentation compared to the plane channel. It was found that when the obstacle is placed in the middle of the duct, maximum heat transfer enhancement from channel walls is achieved. Displacement of circular cylinder towards the bottom wall leads to the suppression of the vortex shedding, the establishment of a steady flow and a reduction of both wall heat transfer and pressure drop. Performance analysis indicates that the proposed heat transfer enhancement mechanism is beneficial for low-Prandtl-number fluids

Heat Transfer Augmentation in a Straight Channel via Two Oscillating Circular Cylinders

We consider flow-through systems in which the characteristic length is limited such that turbulent flow is not reached even at high fluid velocities, i.e., the flow remains laminar. Inthese flow regimes, inducing circulation or vortices in the flow enhances mixing and heat transfer. These can be created by placing obstacles in the flow path, for example. Heat transfer enhancement in a channel via a single stationary and oscillating cylinder was considered previously. Here, heat transfer augmentation by using two oscillating cylinders is investigated systematically and the results compared with the results for a single cylinder. Fully developed fluid flow with a parabolic velocity profile enters the channel in which two oscillating cylinders (blocking ratio of three) are placed a distance of 8D from the inlet. In the simulation, the Reynolds number was fixed at 900 (based on the channel hydraulic diameter) and the Prandtl number at 1. The optimal frequency for each condition was identified by measurement of the average Nusselt number curve over a period of oscillation. In comparison with a straight channel, using this mechanism improves heat transfer considerably, but placing a single cylinder with diameter of at the middle of channel is more efficient. Because the cylinders are offset, the results showed that the generated vortices are suppressed as a result of interaction with the walls. On the other hand, the vortices generated at the channel center are restricted to the middle of the channel and cannot move toward the walls in order to agitate the thermal boundary layer and increase heat transfer. Therefore, the generated vortices are not as effective in enhancing heat transfer as placing one cylinder with diameter of along the channel centerline, as considered previously [1, 2]

A comparative study of pharmaceutical institutions in Iran and abroad

Introduction: In different countries, various organizations and associations are active in the field of pharmacy. These activities mainly consist of policy-making, implementation, training and supervision. In Iran, different tasks are concentrated in one or two institutions; and the active presence of the private sector is not tangible. On the other hand, in developed countries, tasks are divided between public and private institutions. In this article, by investigating and comparing these institutions in different countries and drawing conclusions, systems for dividing tasks with greater efficiency will be achieved. Methods and Results: The workgroup on "Investigating Pharmaceutical Institutions" of Pharmaceutical-Strategic-Studies-Office conducted a study on the responsibilities of each of these institutions, their target population, efficiency rate on the defined objectives in policy, implementation, monitoring and education areas in Iran, neighboring countries and developed countries, as well as their different and similar duties with each other. In this review article, several searches have been done in databases such as PubMed, Google Scholar, Scopus, specialized books as well as websites related to each of these institutions. The results show that in developed countries an average of six pharmaceutical associations exist, all of which are active in the field of education. In the United States, an organization that approves the competency of pharmacists and issues pharmacy establishment permits has been separated from overseeing organizations. In Japan, other than the Health Ministry as a policy-maker and a special council for legislative purposes, a formal overseeing institution, an Office of Health Assessment and two associations with a scientific-trade and research approach are active. In Australia, one third of the associations are active in the area of law enforcement; and the organization which is active in the field of policy-making and supervision does not have any executive activities. In the European Union, one institution has a role in the field of macro policy-making and two associations are involved in micro policy-making. In India and Pakistan, practically all affairs are carried out in the governmental format; NGOs operate in the field of education, research and government consultation. Overall, China is the most similar to Iran

Simple determination of Sudan dyes in fruit juice and spices by microfunnel-filter-based emulsification microextraction followed by high performance liquid chromatography

In this work, a rapid method termed as microfunnel-filter-based emulsification microextraction is coupled with high performance liquid chromatography for a simple determination of the banned Sudan dyes (I, II, and III) in fruit juice, spice, and water samples. According to the method, in order to speed-up the extraction and concentration of the target analytes, a micro-volume of a low-density organic solvent (1-octanol) is dispersed into an aqueous sample solution (45 mL), and a simple separation of the extractant phase is obtained using a syringe filter and microfunnel. The method provides a low-toxic extraction, it is centrifuge-less, and the extraction process is totally performed in a few minutes. The influencing factors including the type of organic solvent, number of extraction cycles, pH of the sample solution, and volume of the extraction solvent are investigated to achieve the optimal conditions. A good linearity (in the range of 0.7–1000 ng mL−1 (R2 > 0.995)) and a low limit of detection (in the range of 0.2-0.5 ng mL−1) are obtained, the extraction recovery is in the range of 94-107%, and the developed method provides a high enrichment factor (in the range of 294-354)

Heat transfer enhancement in a straight channel via a rotationally oscillating adiabatic cylinder

Heat convection from the uniformly heated walls of a straight channel in presence of a rotationally oscillating cylinder (ROC) is simulated at Re = 100. Heat transfer enhancement due to vortex shedding from the ROC is investigated. Systematic studies are performed to explore the rotation angle and frequency influences on heat transfer by varying the latter in range of the lock-in regime and the former from 0 to 2π/3. All simulation results are based on the numerical solutions of two-dimensional, unsteady, incompressible Navier–Stokes and energy equations using an h/p type finite element algorithm. Considering time periodicity of the resulting flow and temperature fields, time averaged wall Nusselt number is reported to quantify the heat transfer enhancement for Pr = 0.1, 1.0, 5.0 and 10.0 fluids. Performance analyses of the ROC device based on its total power consumption and heat transfer enhancement are also presented