relationships between soil factors and vegetation types in playa of damghan was investigated. six vegetationtypes including artemisia.sieberi, arundo. sp, artemisia.sieberi-peganum.harmala, alhagi.cammelerom,artemisia.sieberi-petropyron.sp, tamarix.passerinoides-halocnemum strobilaceum. one bare land was recognized inthe study area and the research was conducted within mentioned types. canopy p...

heavy metal contamination around the national iranian lead and zinc company (nilz) in zanjan province was evaluated in this paper. collected data were used to appraise the degree of soil contamination and also the source of pollution in the study area based on geoaccumulation index (igeo), and enrichment factor (ef). the levels of fe, zn, cd and pb in the samples exceed those reported in litera...

numbers of persian leopards have considerably decreased in recent years and for this reason it has been categorized as endangered in the iucn classification. habitat destruction is believed to be the main cause of the species population decline. hence, attempts to preserve the remaining habitats of this kind of animal effectively are deemed essential in reversing its downgrading trend. to hit t...

conclusions four major dietary patterns were identified in the present studied population that can be used to provide tangible dietary advice for the elderly. results four major dietary patterns were identified in the studied population: 1) healthy pattern, characterized by a higher intake of vegetables, tomato and tomato sauce, vegetable oil, olive, and fruits; 2) unhealthy pattern, characteri...

Objective: The purpose of this study was to identify factors influencing student’s achievement motivation. Statistical population of this research consisted of Agriculture Ms.c students in Tehran university (N=712). Methods: A random sampling method was used to collect data From 175 students applying Cochran's formula. The main tool to collect data was a researcher made questionnaire. Content v...

The aim of the current study was twofold: (1) to validate the internal structure of the general English (GE) section of the university entrance examination for Ph.D applicants into the English programs at state universities in Iran (Ph.D. UEE), and (2) to examine the factor structure invariance of the Ph.D. UEE across two proficiency levels. Structural equation modeling (SEM) was used to analyz...

در این مقاله یک مدل ریاضی برای مسئله سیستم تولیدی همکارانه ساخت بر اساس سفارش با رعایت انصاف تخصیص بار‌های تولید طراحی شده است. اهداف اصلی مدل، کمینه‌سازی هزینه‌‌های کل و حداکثر استفاده از منابع به‌منظور عادلانه شرایط عدم­قطعیت کنترل پارامتر‌های غیرقطعی روش برنامه‌ریزی فازی ‌شده نتایج نشان می‌دهد افزایش نرخ عدم‌قطعیت، می­یابد. ازآنجاکه ظرفیت کارخانه‌ها ثابت است، مقدار تقاضا، هر کارخانه نیز می­ی...

روش الکتریکی به عنوان یک بررسی ژئوفیزیکی می‌تواند پارامترهای زمین‌شناسی شامل خردشدگی، شاخص دگرسانی توده سنگ، درصد اشباع، کیفیت آب زیرزمینی و . را خوبی نمایش دهد. این پارامترها نقش مهمی در طبقه‌بندی مهندسی سنگ از طریق تأثیر بر دو (RQD) مقاومت (GSI)، کانه‌زایی عناصر نیز نحوه حفاری دارند. مقاله با استفاده سونداژ قائم لایه‌های زیرسطحی تعیین متعاقباً مذکور توده‌سنگ‌های آذرآواری آنومالی III کانسار نار...