فهرست مطالب

نشریه ماشین های کشاورزی
سال دوازدهم شماره 2 (پیاپی 24، تابستان 1401)

  • تاریخ انتشار: 1401/04/01
  • تعداد عناوین: 12
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  • زینب عزیزپور، حسنعلی واحدی، علی نجات لرستانی* صفحات 107-118

    استراتژی مدیریت تلفیقی آفات (IPM)، به پایش پیوسته جمعیت آفات وابسته است، این کار نه تنها زمان بر است، بلکه وابستگی زیادی به داوری انسان دارد و پر هزینه نیز می باشد. استفاده از روش های هوش مصنوعی به جای تصمیم گیری های دستی و انسانی، علاوه بر این که سبب افزایش بهره وری می گردد، از دقت بالایی نیز برخوردار است. پسته، یک محصول تجاری است و هر ساله خسارت زیادی توسط حشرات به تولیدکنندگان این محصول وارد می شود. گروهی از آفات پسته عمدتا از میوه پسته تغذیه می کنند، که از این گروه زنجرک پسته، دارای اهمیت زیادی می باشد. در این تحقیق زنجرک پسته به عنوان حشره هدف جهت شناسایی انتخاب شد. برای جمع آوری نمونه ها از کارت های زرد چسبنده استفاده شد. 357 خصوصیت رنگی و 20خصوصیت شکلی برای شناسایی زنجرک پسته به وسیله الگوریتم پردازش تصویر استخراج شد. خصوصیات رنگی به دو دسته ی خصوصیات مربوط به میانگین و انحراف معیار و خصوصیات مربوط به شاخص های سبزی تقسیم شدند. از 17 فضای رنگی مختلف مثل RGB، HSV و غیره برای استخراج خصوصیات و از روش هیبرید شبکه عصبی مصنوعی-الگوریتم بهینه سازی ازدحام ذرات (ANN-PSO) برای انتخاب خصوصیات موثر استفاده گردید. خصوصیات موثر انتخابی جهت طبقه بندی حشرات عبارتند از: شاخص رنگی برای پوشش گیاهی استخراجی مربوط به فضای رنگی HSL، شاخص تفاضل نرمال شده مربوط به فضای رنگی LCH، کانال خاکستری مربوط به فضای رنگی YCbCr، شاخص مولفه دوم منهای مولفه سوم مربوط به فضای رنگی YCbCr، مساحت و میانگین مولفه های اول، دوم و سوم فضای رنگی Luv. نرخ شناسایی الگوریتم پردازش تصویر طراحی شده، 72/99درصد کل اشیا (زنجرک پسته، سوسک چوب خوار قرمز پسته و سایر حشره های غیر هدف و متفرقه) می باشد. شبکه های عصبی مصنوعی، توانایی طبقه بندی حشرات به سه کلاس (زنجرک پسته، سوسک چوب خوار قرمز پسته و سایر حشره های غیر هدف و متفرقه) و دو کلاس (زنجرک پسته و سوسک چوب خوار قرمز پسته) به ترتیب با دقت 53/91 و 59/99 درصد را دارند.

    کلیدواژگان: پردازش تصویر، زنجرک پسته، شبکه عصبی مصنوعی، شناسایی
  • ایمان گلپور، پرویز احمدی مقدم*، علی محمد نیکبخت صفحات 119-130

    در این کار تحقیقاتی، تحلیل انرژی و اکسرژی سامانه تولید بخار شرکت آبمیوه پاکدیس ارومیه با چهار دیگ بخار بررسی شد و با استفاده از معادلات تعادل جرم، انرژی و اکسرژی برای هر یک از اجزای سامانه، توابع هدف ترمودینامیکی شامل بازده اکسرژی، نرخ تخریب اکسرژی، نرخ تلفات اکسرژی و نرخ پتانسیل بهبود آن ها بر اساس قانون اول و دوم ترمودینامیکی مورد ارزیابی قرار گرفت. پس از اکتساب داده ها، تحلیل انرژی و اکسرژی این سامانه با حل معادلات مربوطه با کمک روابط خواص ترمودینامیکی همراه با برنامه نویسی در نرم افزار EES صورت پذیرفت. نتایج نشان داد که بیشترین بازده اکسرژی 44/98 درصد، مربوط به توزیع کننده بخار (O) سامانه با نرخ پتانسیل بهبود 51/1 کیلووات و نرخ تخریب اکسرژی 38/28 کیلووات بود، و همچنین پمپ (M) قبل از دیگ بخار چهارم با بازده اکسرژی 69/19 درصد دارای کمترین مقدار بازده اکسرژی بود به طوری که مقادیر 55/12 و 93/11 کیلووات به ترتیب برای نرخ تخریب اکسرژی و نرخ پتانسیل بهبود آن حاصل شد. بیشترین نرخ تخریب اکسرژی سامانه را دیگ بخار اول با مقدار 80/12391 کیلووات با بازده 55/19 درصد و نرخ پتانسیل بهبود 26/10295 کیلووات دارا بود. طبق نتایج حاصله، بیشترین و کمترین مقدار نرخ تلفات اکسرژی سامانه با مقادیر 90/446 و 47/0 کیلووات به ترتیب برای دیگ بخار سوم (L) و منبع انبساط (F) به دست آمد.

    کلیدواژگان: بازده اکسرژی، سامانه تولید بخار، نرخ پتانسیل بهبود اکسرژی، نرخ تخریب اکسرژی
  • حامد فرزانپور، سید صادق سیدلو هریس*، حبیبه نعلبندی صفحات 131-146

    تهویه یک متغیر کلیدی برای بهینه سازی شرایط محیط داخلی مرغداری است که با کنترل عواملی مانند درجه حرارت، سرعت هوا و غلظت گازهای موجود، می تواند از تلفات طیور جلوگیری کند. در حال حاضر دستورالعمل های دقیقی در راستای طراحی و ساخت سالن های مرغداری و سیستم های تهویه با هدف کنترل دقیق شرایط محیطی توسعه نیافته است. در این تحقیق در یک مرغداری طولی و با تهویه مکانیکی فشار منفی، توزیع دما و الگوهای جریان هوا با استفاده از دینامیک سیالات محاسباتی شبیه سازی شد و با استفاده از شبیه ساز توسعه یافته راهکارهایی برای بهبود سیستم تهویه ارایه شد. در توسعه شبیه ساز مذکور همه شرایط مرزی از طریق اندازه گیری های تجربی در طول یک دوره 24 ساعته به دست آمد. اعتبارسنجی نتایج شبیه ساز، در 13 نقطه آزمون شد و مشخصه های آماری بیان کننده دقت پیش بینی مانند RMSE، بین دمای اندازه گیری شده و پیش بینی شده در محدوده 405/0 تا 29/1 قرار داشت و شبیه ساز قادر بود تغییرات دمای نقاط مختلف سالن مرغداری را با دقت 6/0 درجه پیش بینی نماید. نتایج شبیه ساز نشان داد که در مرغداری مورد مطالعه پروفیل دما در سطح استقرار طیور، حدود 18 درجه در نقاط مختلف سالن تفاوت دمایی وجود دارد و سرعت هوا در نواحی مرکزی سالن بیش از یک متر بر ثانیه می باشد. بنابراین در مرحله بعدی از شبیه ساز توسعه یافته برای بهبود تهویه سالن مرغداری مذکور استفاده و تغییراتی در محل استقرار ورودی های هوا و سرعت هوای اعمال و در نهایت با اصلاحات انجام شده توزیع دما در مرغداری نسبت به حالت اولیه یکنواخت تر شد و دمای هوا در محدوده 291 تا 297 کلوین (معادل 18 تا 24 درجه سانتی گراد) و در حد مطلوب قرار گرفت. هم چنین پس از اصلاحات انجام شده، سرعت هوا در اغلب نقاط سالن در محدوده ی 23/0 تا 46/0 متر بر ثانیه قرار داشت که در محدوده توصیه شده می باشد. بنابراین برای طراحی و ساخت مرغداری ها و نصب سیستم های تهویه، شبیه ساز توسعه داده شده دارای عملکرد و دقت خوبی است.

    کلیدواژگان: توزیع دما، تهویه، سرعت هوا، شبیه سازی، مرغداری، یکنواختی
  • آیسودا میرزایی، محسن سلیمانی*، هوشنگ بهرامی، مجتبی نوروزی مصیر صفحات 147-157

    هدف از این مطالعه، آزمون هضم مشترک کود مرغی با محتویات شکمبه گاوی و روده مرغ و محتویات آن، در هاضم های بی هوازی ناپیوسته، به هدف افزایش تولید زیست گاز و همچنین مطالعه اثر برگرداندن لجن حاصله به چرخه تولید، بر مقدار تولید زیست گاز و کاهش مدت زمان انتطار برای تولید گاز بود. آزمایش در دو مرحله انجام شد. در مرحله اول اثرات هضم مشترک کود مرغی با محتویات شکمبه گاوی و روده مرغ و محتویات آن، هرکدام در سه سطح (10، 20 و 30 درصد وزنی کود مرغی) مورد بررسی قرار گرفت و در مرحله دوم، پس از رسیدن همه تیمارها به پایان زمان ماند هیدرولیکی، قسمت مایع لجن حاصل از تیمارهای مرحله اول، به هاضم های مرحله دوم آزمایش وارد شد. در این مرحله نیز سه تیمار (تیمار شاهد (تامین کل آب مورد نیاز با آب خالص)، تامین 50 و 100 درصد از آب مورد نیاز توسط مایع لجن) آزمون شدند. با توجه به نتایج، هضم مشترک محتویات شکمبه گاوی با کود مرغی اثر معنی داری بر میزان افزایش تولید زیست گاز نداشت اما هضم مشترک روده مرغ و محتویات آن با کود مرغی (حداقل به میزان 10 درصد وزنی) اثر معنی داری بر افزایش تولید زیست گاز داشته و می تواند میزان گاز حاصله را حداقل به میزان دو برابر افزایش دهد. تیمار (کود مرغی +20% روده مرغ و محتویات آن) بیشترین مقدار تولید زیست گاز را به میزان تقریبی ml.grVS-1 305 نتیجه داد. اثر برگرداندن لجن حاصله به چرخه هضم، هم بر مقدار تولید گاز و هم بر روی مدت زمان انتظار برای تولید گاز، در سطح 5 درصد معنی دار بود؛ اما تفاوت معنی داری بین دو تیمار تامین 50 درصدی و 100 درصدی آب مورد نیاز توسط آب لجنی از لحاظ تسریع در شروع تولید گاز و همچنین میزان گاز تولید شده دیده نشد. بنابراین استفاده از آب لجنی برای تامین حداقل 50 درصد از آب مورد نیاز هضم، علاوه بر افزایش میزان گاز تولیدی و کم کردن مدت زمان انتظار برای شروع تولید گاز، مصرف آب را نیز حداقل به میزان 50 درصد کاهش می دهد.

    کلیدواژگان: انرژی تجدیدپذیر، هضم بی هوازی، هضم ترکیبی، هاضم ناپبوسته
  • علی مقیمی، آمنه سازگارنیا، محمدحسین آق خانی* صفحات 159-167

    در سال های اخیر تولید پسته توسط آفتی به نام پسیل تهدید شده است. هدف از انجام این تحقیق انتخاب باندهای طیفی مناسب جهت تشخیص برگ های آلوده به آفت پسیل می باشد. برای این منظور از 160 برگ سالم و 160 برگ بیمار در 64 باند طیفی در ناحیه بین 400 تا 1100 نانومتر با قدرت تفکیک طیفی حدودا 10 نانومتر طیف‎نگاری انجام شد. از روش جنگل های تصادفی برای مرتب سازی طول موج ها بر اساس قدرت تفکیک بین برگ های سالم و بیمار استفاده شد. پس از شناسایی و مرتب سازی طول موج ها بر اساس میزان اهمیت، طول موج های دارای بیشترین اهمیت توسط یک الگوریتم خوشه بندی در شش خوشه تقسیم بندی شدند به طوری که میانگین طول موج های هر خوشه ها حداقل 50 نانومتر از یکدیگر فاصله داشته باشند. میانگین طول موج های قرار گرفته در شش خوشه به ترتیب اهمیت عبارت بود از: 710، 791، 858، 598، 468، و 1023 نانومتر. برای تبدیل داده های فراطیفی به چندطیفی، از بازتابش های به دست آمده در فاصله 15± نانومتری این مراکز میانگین گیری انجام گرفت و داده های بازتابش به دست آمده از دیگر طیف ها حذف شد. الگوریتم ماشین بردار پشتیبان برای طبقه بندی برگ های سالم و بیمار با استفاده از داده های فراطیفی و چند طیفی به دست آمده در این پژوهش به کار گرفته شد. دقت طبقه بندی با استفاده از تمام 64 طول موج (داده های فراطیفی) 91/90 درصد و با استفاده از 6 طول موج (داده های چندطیفی) 69/88 درصد بود. اختلاف بسیار کم (حدود 2 درصد) در میزان دقت طبقه بندی نشان دهنده صحت شیوه ارایه شده در این پژوهش برای کاهش ابعاد داده های فراطیفی می باشد. علاوه بر کاهش ابعاد داده، تعیین باندهای طیفی مناسب از میان داده های فراطیفی گامی موثر در طراحی و ساخت حسگری چندطیفی جهت تشخیص بیماری گیاهان می باشد.

    کلیدواژگان: انتخاب ویژگی، پسته، جنگل های تصادفی، طیف سنجی، فراطیفی
  • اسماعیل چاوشقلی*، شمس الله عبدالله پور، حمیدرضا قاسم زاده صفحات 169-179

    آفتاب‏گردان آجیلی معمولا بدون کمباین برداشت در رطوبت بالا برداشت می ‏شود لذا در تحقیق حاضر یک واحد کوبنده با ترکیب متغیرهای مناسب برای جداسازی دانه آفتاب‏گردان و طبق‏ ها با ظرفیت بالا و آسیب‏دیدگی پایین دانه، طراحی و ساخته شد. کوبنده برای شرایط گوناگون قابلیت تنظیم و بهینه ‏سازی دارد که برای توسعه ماشین برداشت با ظرفیت بالا اهمیت فراوانی دارد. آزمایش‏ های ارزیابی و بهینه ‏یابی با استفاده از روش سطح پاسخ طراحی شد. تاثیرات سرعت‏ دورانی کوبنده 380، 280 و 180 (دور در دقیقه)، نرخ تغذیه 4000، 3000 و 2000 (کیلوگرم در ساعت) و رطوبت (رطوبت برداشت) 60%، %45 و %30 (بر پایه تر) روی عملکرد کوبنده مورد بررسی قرار گرفت. بازده کوبش (%)، بازده جداسازی (%) و آسیب‏ دیدگی دانه (%) به ‏ترتیب در محدوده 12/96 تا 89/99، 71/56 تا 82/69 و 49/0 تا 25/1 به ‏دست آمد. نتایج تجزیه و تحلیل واریانس نشان داد که مدل‏ های ایجاد شده از لحاظ آماری و اثر محتوی رطوبت روی بازده کوبش و آسیب‏ دیدگی دانه و اثر نرخ تغذیه روی بازده جداسازی در سطح اطمینان 95% معنی ‏دار بودند. منحنی‏ های سطح پاسخ مشخص کردند که با کاهش محتوی رطوبت، بازده کوبش و جداسازی افزایش و آسیب‏ دیدگی دانه‏ ها کاهش پیدا کرد. هدف از بهینه ‏یابی رسیدن به حداکثر بازده کوبش و جداسازی و حداقل کردن آسیب ‏دیدگی دانه‏ ها است که مقادیر بهینه شده متغیرها در نرم افزار Design Expert برای سرعت دورانی 134/292 دور در دقیقه، نرخ تغذیه 2000 کیلوگرم در ساعت و محتوی رطوبت 74/30% (بر پایه تر) به‏ دست آمد.

    کلیدواژگان: آفتاب‏گردان آجیلی، بهینه‏ سازی، روش سطح پاسخ، سرعت ضربه‏ ای بحرانی، عملکرد، واحد کوبنده
  • مهدی حسن نیا سماکوش، سید رضا موسوی سیدی*، علیرضا مهدویان صفحات 181-192

    دستگاه اندازه گیر تلفات دانه کمباین وسیله ای است که با نصب آن روی کمباین، می توان از میزان تلفات در واحدهای جداکننده و تمیزکننده آگاهی یافت. از جمله مزایای این دستگاه این است که به کاربر این امکان را می دهد با داشتن یک میزان قابل قبول از تلفات دانه، بیشینه سرعت پیشروی را انتخاب نمود. در تحقیق حاضر از صفحه مشبکی به ابعاد 60×100 سانتی متر مربع که قطر شبکه های آن 7 میلی متر بوده برای جداسازی شلتوک از کاه و کلش استفاده شد. دانه های جداشده از این قسمت روی صفحه زیرین می ریزند که از طریق 4 شبکه جداگانه روی حسگرهای مورد نظر سقوط کرده و پالس های مورد نظر از حسگرها به کاربر ارسال و در صفحه نمایشگر نشان داده می شود. میزان تلفات دانه در انتهای کمباین با استفاده از حسگر پیزوالکتریک که دارای حساسیت بالا در تشخیص دانه های شلتوک می باشد بررسی گردید. نمونه مورد آزمایش در این تحقیق یک کیلوگرم کاه و کلش به همراه 52گرم شلتوک است که معادل تلفات سه درصدی (میانگین تلفات انتهای کمباین در کشورهای پیشرفته 14/2 درصد است) در انتهای کمباین می باشد. تیمارهای مورد استفاده، سرعت دورانی صفحه مشبک، شیب صفحه مشبک و رطوبت نمونه بوده که هرکدام در سه سطح و در سه تکرار مورد آزمایش قرار گرفت. سپس با استفاده از طرح کاملا تصادفی تجزیه و تحلیل آماری انجام شد. برای تجزیه و تحلیل آماری عملکرد دستگاه، از نرم افزار GenStat استفاده شد. نتایج تحقیقات نشان داد مناسب ترین کارایی دستگاه در سرعت دورانی 100 دور در دقیقه صفحه مشبک، رطوبت 12 درصدی نمونه آزمایشی و شیب 25 درجه ای صفحه مشبک معادل 51/95% می باشد، که مهم ترین دلیل آن ارتعاش زیاد در بیشینه سرعت دورانی صفحه مشبک و پراکندگی نمونه آزمایشگاهی به دلیل رطوبت پایین آن می باشد. کمترین میزان کارایی دستگاه نیز در سرعت دورانی 100 دور در دقیقه، رطوبت 24 درصدی نمونه آزمایشی و شیب 45 درجه ای صفحه مشبک 70% می باشد.

    کلیدواژگان: پیزوالکتریک، تلفات کمباین برنج، حسگر، صفحه مشبک، طراحی
  • ابراهیم البوعطیوی، عباس عساکره*، حسن ذکی دیزجی، یعقوب منصوری صفحات 193-206

    در این مطالعه مصرف انرژی مستقیم در تولید تخته نیوپان از باگاس نیشکر و امکان جایگزینی آن با ضایعات کشت و صنعت نیشکر دعبل خزاعی و صنایع جانبی آن بررسی گردید. انرژی مستقیم مصرفی به ازای هر مترمکعب نیوپان تولیدی 829/5 گیگاژول محاسبه شد که گاز طبیعی، برق و سوخت دیزل به ترتیب 52/78، 87/18 و 61/2 درصد آن را تشکیل می دهند. پیت و خرده چوب های حاصل از ضایعات کارخانه نیوپان سازی، برگ و پوشال نیشکر، باگاس مازاد و ویناس حاصل از تولید الکل از ملاس نیشکر به عنوان ضایعات جهت تولید انرژی در نظر گرفته شدند. خاکستر، رطوبت، ارزش حرارتی خالص (با استفاده از بمب کالری متر) و مقدار ضایعات خشبی و همچنین پتانسیل تولید زیست گاز از تخمیر بی هوازی ویناس اندازه گیری و محاسبه شد. نتایج نشان داد با استفاده از پسماند خشبی کارخانه نیوپان سازی و کشت و صنعت دعبل خزاعی می توان 33/4 برابر کل انرژی گاز مصرفی در کارخانه نیوپان سازی انرژی حرارتی با بازده 60 درصد تولید کرد. همچنین با استفاده از ضایعات کارخانه نیوپان سازی و باگاس، می توان کل گاز و برق مصرفی کارخانه نیوپان سازی را جایگزین کرد. بررسی حجم ویناس و پتانسیل تولید زیست گاز از آن نشان داد پتانسیل تولید انرژی معادل 8824319 مترمکعب گاز طبیعی در سال وجود دارد.

    کلیدواژگان: ارزش حرارتی، پیت، زیست گاز، نیشکر، ویناس
  • نسیم صداقت حرفه، علی محمد نیکبخت*، حسین مبلی، علیرضا کیهانی، احمد پیری صفحات 207-218

    صنعت تغلیظ یکی از بزرگ ترین و انرژی برترین صنایع تبدیلی در بخش کشاورزی است. در این مطالعه فرآیند تغلیظ آب آلبالو با استفاده از تحلیل انرژی و اکسرژی ارزیابی شد و علاوه بر تعیین هدررفت های انرژی، ناکارآمدی های ترمودینامیکی در هریک از زیرسامانه ها تعیین شدند. همچنین جهت دقیق بودن هرچه بیشتر محاسبات، تمام تجهیزات دمانگاری شدند. پارامتر اقتصاد بخار 63/2 و کل نرخ هدررفت انرژی از خط تغلیظ 82/4920 کیلووات محاسبه شد. نتایج نشان داد که هدررفت انرژی از برج خنک کننده با 39/73 درصد از کل هدررفت ها، بیشترین مقدار را به خود اختصاص داده است. مقدار کل تخریب اکسرژی برای خط تغلیظ 85/1045 کیلووات و بازده اکسرژی کل 76/75 درصد محاسبه شدند. بیشترین مقدار تخریب اکسرژی در چگالنده بارومتریک با مقدار 71/346 کیلووات به دست آمد. بر اساس نتایج به دست آمده، احیا و استفاده از سربخار مرحله ی آخر، به عنوان راه حلی برای کاهش هدررفت های برج خنک کننده و کاهش نرخ تخریب اکسرژی در چگالنده پیشنهاد می شود.

    کلیدواژگان: آلبالو، اتلاف انرژی، تخریب اکسرژی، کنسانتره
  • احمد حیدری*، علی قدمی فیروزآبادی صفحات 219-229

    خاک ورزی مرسوم به طور گسترده در مناطق چغندرکاری استفاده می شود. به هرحال خاک ورزی مرسوم کارگر و ماشین های بیشتری استفاده کرده و اثر منفی روی خاک و محیط زیست دارد. بدین منظور تحقیقی برای بررسی اثر روش های خاک ورزی و کم آبیاری بر عملکرد کمی و کیفی و بهره وری آب چغندرقند در سامانه آبیاری قطره ای در خاکی با بافت متوسط در ایستگاه تحقیقاتی اکباتان استان همدان در سال زراعی 98-1397 به اجرا درآمد. این تحقیق به صورت طرح کرت های نواری در قالب بلوک های کامل تصادفی در سه تکرار اجرا شد. عامل افقی، روش های خاک ورزی شامل: T1- گاوآهن برگرداندار در پاییز+ سیکلوتیلر در بهار (شاهد)، T2- زیرشکن و گاوآهن برگرداندار در پاییز + سیکلوتیلر در بهار، T3- خاک ورز مرکب (گاوآهن قلمی + غلطک) در پاییز + سیکلوتیلر در بهار، T4- خاک ورز مرکب (گاوآهن چیزل با تیغه های پنجه غازی + غلطک) در پاییز+ سیکلوتیلر در بهار و عامل عمودی، تیمار آبی در چهار سطح شامل: I100- تامین 100 درصد، I90- تامین 90 درصد، I80- تامین 80 درصد و I70- تامین70 درصد نیاز آبی بود. پارامترهای مقاومت به نفوذ در خاک (شاخص مخروطی خاک)، میزان حجم آب مصرفی، عملکرد ریشه، شکر، شکر سفید و قند ملاس اندازه گیری شدند. نتایج نشان داد که اثر روش های مختلف خاک ورزی، تیمار آبی و اثرات متقابل آن ها در سطح احتمال 1 درصد بر عملکرد ریشه، عملکرد شکر، عملکرد شکر سفید و بهره وری آب معنی دار شدند. از نظر آماری اختلاف معنی دار بین تیمار T4 و روش مرسوم (T1)  و تیمار T2 از نظر عملکرد ریشه چغندرقند مشاهده نشد. تیمارهای  T4(با میانگین عملکرد 686/50 تن در هکتار) و T1 (با میانگین عملکرد 507/50 تن در هکتار) بیشترین عملکرد ریشه چغندرقند را به خود اختصاص دادند. همچنین روش خاک ورزی (T4) نسبت به روش رایج خاک ورزی (T1) به ترتیب باعث کاهش 7/14درصدی در مصرف سوخت و افزایش ظرفیت مزرعه ای به میزان4/52 درصد شد. در روش خاک ورزی T4، تیمارهای آبی I100، I90 وI80  به ترتیب با میانگین بهره وری آب 113/6، 087/6 و 523/5 کیلوگرم به ازای یک متر مکعب مصرف آب بیشترین اثر را بر افزایش بهره وری آب بر اساس شاخص عملکرد ریشه داشتند. در حالی که تفاوت معنی دار بین آن ها مشاهده نشد. نتیجه این که در روش خاک ورزی T4 با تامین 80% نیاز آبی چغندرقند بعد از استقرار گیاه (حدودا از اواسط فصل رشد) حدود 12% (1207 متر مکعب) در مصرف آب بدون کاهش معنی دار در بهره وری آب بر اساس شاخص عملکرد ریشه صرفه جویی کرد.

    کلیدواژگان: آبیاری قطره ای، زیرشکن، سیکلوتیلر، گاوآهن قلمی، مقاومت به نفوذ در خاک
  • محسن فریدونی، حسین حاجی آقاعلیزاده* صفحات 231-240

    با افزایش جمعیت جهان، نیاز به تولید مواد غذایی بیشتر نیز افزایش می یابد. فناوری پلاسما یکی از روش هایی است که می تواند رشد گیاه را بهبود بخشد. پلاسمای سرد در افزایش شاخص های رشد و جوانه زنی موثر است. در این مقاله، تاثیر پلاسمای سرد بر پایه تخلیه کرونا بر جوانه زنی ارقام نخود عادل، منصور و آزاد بررسی شد. در روش تخلیه کرونا، از خلا نسبی استفاده شد. پژوهش حاضر در قالب آزمایش فاکتوریل بر پایه طرح کامل تصادفی انجام شد. بذرهای مواجه با پلاسما و بذرهای شاهد در شرایط یکسان برای جوانه ‎زنی نگهداری شدند. نتایج نشان داد سرعت جوانه زنی در بذرهایی که به مدت 60 ثانیه مواجهه با پلاسمای سرد داشتند، بیشتر از بذرهای بدون مواجهه بود. همچنین بذرهای ارقام عادل و منصور که به مدت 30 ثانیه در مواجهه با پلاسمای سرد قرار گرفتند، دارای طول ریشه بیشتری نسبت به بذرهای بدون مواجهه بودند. پس از تجزیه و تحلیل آماری، مشخص شد که طول ریشه در شرایط یکسان، در مدت زمان مواجهه 30 ثانیه در معرض پلاسمای سرد، دارای اختلاف معنی داری در سطح 5% نسبت به حالت های مواجهه 60 ثانیه و بدون مواجهه با پلاسمای سرد دارد. تصاویر میکروسکوپی از سطح خارجی و بافت داخلی سلول بذر در نمونه ها مورد بررسی قرار گرفت. بررسی ها نشان دادند که سطوح خارجی بذرهای در معرض پلاسمای سرد نسبت به شاهد هموارتر، دارای برجستگی کمتر و زاویه سطح تماس کمتری هستند. این تغییر می تواند خاصیت آب دوستی را افزایش دهد. اما در مواجهه بذر با پلاسمای سرد، تغییری در بافت داخلی سلول مشاهده نگردید.

    کلیدواژگان: پلاسمای سرد، تصویر میکروسکوپی، جوانه زنی، نخود
  • اعظم رضایی، حسن مسعودی*، حسن ذکی دیزجی، محمداسماعیل خراسانی فردوانی صفحات 241-252

    برای طراحی بهینه و اصلاح ساختار اکسل وسایل نقلیه دانستن بارهای وارده بر آن در شرایط کاری ضروری است. این پژوهش به دنبال اعلان نیاز پژوهشی شرکت کمباین سازی ایران مبنی بر تحلیل و محاسبه نیروهای وارد بر بدنه، محورها و چرخ های کمباین انجام شد. سامانه ی الکترونیکی ساخته شده شامل کوپلینگ فولادی، نیروسنج فشاری، مدار تقویت کننده ولتاژ، دیتالاگر و رایانه بود. نیروسنج به کمک کوپلینگ بر میانه اکسل عقب کمباین جاندیر 955 نصب گردید. آزمون های ارزیابی عملکرد سامانه در حالت های سکون و حرکت کمباین در جاده آسفالت، جاده خاکی و مزرعه با سرعت های پیشروی متفاوت به صورت آزمایش فاکتوریل در قالب طرح کاملا تصادفی و در پنج تکرار انجام شد. مطابق نتایج میانگین بارهای استاتیکی وارده بر اکسل در حالت موتور روشن و موتور خاموش به ترتیب 908/14 و 905/14 کیلونیوتن بود که تفاوت معنی داری در سطح یک درصد نداشتند. میانگین بارهای عمودی وارده بر اکسل حین حرکت در جاده آسفالت با سرعت های 10، 15 و 20 کیلومتر بر ساعت به ترتیب 20/15، 27/15 و 28/15 کیلونیوتن، حین حرکت در جاده خاکی با سرعت های 2، 4 و 6 کیلومتر بر ساعت به ترتیب 57/17، 99/17 و 15/18 کیلونیوتن و هنگام دروی گندم با سرعت های 3، 4 و 5 کیلومتر بر ساعت به ترتیب 47/16، 01/18 و 78/17 کیلونیوتن به دست آمد. بیشینه بار وارده بر اکسل حدود 50 کیلونیوتن و در جاده خاکی بود. در مجموع نتایج ارزیابی ها نشان داد که عملکرد سامانه ساخته شده قابل قبول بوده و می توان از آن برای اندازه گیری بارهای عمودی وارده به اکسل عقب کمباین استفاده کرد.

    کلیدواژگان: اکسل عقب، سامانه الکترونیکی، کمباین غلات، کوپلینگ، نیروسنج
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  • Z .Azizpour, H. Vahedi, A. N. Lorestani * Pages 107-118
    Introduction

    Pistachio or Green Gold is one of the most important agricultural crops and is especially important for Iranian exports. A group of pistachio's pests mainly feed on pistachio, among which Idiocerus stali is very important. Conventional methods for identifying insects using identification keys are time-consuming and costly. Due to the rapid development of the Pistachio industry, the use of artificial intelligence techniques such as image processing, for identification and population monitoring is highly recommended. On the other hand, little research was carried out on I. stali. Therefore, in this research, I. stali was selected as a target insect for the identification and counting on sticky yellow cards using image processing techniques and artificial neural networks. The purpose of this study was to determine the feasibility of I. stali identification algorithm by image processing, to determine the possibility of separation and counting of I. stali from other non-target insects by artificial neural network and to determine its accuracy in identification of I. Stali.

    Materials and Methods

    Idiocerus stali was selected as the target insect for identification. Sticky yellow cards were used for collecting samples. Taking the photos with the help of a SONY Handycam Camera, which had a 12-megapixel resolution and G lens, was carried out (SONY, HDR-XR500, CMOS, SONY Lens G, Made in Japan). Then insects were counted on each card manually and the data was recorded. The data, which were digital images of yellow sticky cards, were imported into the MatLab R2017b software environment. A total of 357 color properties and 20 shape's features for the identification of I. stali were extracted by an image processing algorithm. Color properties were divided into two categories of mean and standard deviation and characteristics related to vegetation indices. An ANN-PSO (Artificial Neural Network hybrid method-Particle Swarm Optimization) algorithm was used to select the effective features. The selected effective characteristics for insect classification were: Color index for extra collective vegetation related to HSL color space, normalized difference index for LCH color space, gray channel for color space YCbCr, second component index minus third component for color space YCbCr, area and mean of the first, second and third components of color space Luv.

    Results and Discussion

    Comparing the results with the results of Qiao et al. (2008), we found that in his study, which divided the data into three categories, for medium and high-density groups, the detection rate was 95.2% and 94.6%, respectively. On the other hand, in low densities (less than 10 trapped insects); its detection rate was 72.9%, while the detection rate of the classifier system designed in this study for different densities of trapped insects, was identical and equal to 99.59%. Also, comparing the results of this study with Espinoza et al. (2016), we found that their algorithm in whiteflies detection had a high accuracy of about 0.96 on a sticky yellow card, while the Thrips identification algorithm accuracy was 0.92 on a sticky blue card. As stated above, the correct detection rate of I. stali by the algorithm designed in this study was 99.72%.

    Conclusion

    The results showed the feasibility of the new method for identifying the pest insects without destroying them on the farm and in natural light conditions and in a short time and with very high accuracy. This suggests that this algorithm can be applied to the machine vision system and can be used in future in the construction of agricultural robots.

    Keywords: Artificial neural network, Classification, Identification, Image processing
  • I .Golpour, P .Ahmadi Moghaddam *, A. M. Nikbakht Pages 119-130
    Introduction

    Steam generation system is a crucial and essential part of food industries which generates and distributes steam for consumption in domestic production units. Energy analysis based on the first law of thermodynamics was employed as the basic approach to assess energy systems. However, the energy approach does not provide information on the degradation of the energy quality occurring within energy systems and is, therefore, insufficient for sustainable design or optimization goals. Nevertheless, exergy analysis based on both the first and second laws of thermodynamics can overcome shortcomings of energy analysis. In the present study, the performance of equipment of the steam generation system in Pakdis’s juice production Company located in Urmia is investigated. Owing to the energy and exergy analyses, the sites with the highest loss of exergy are identified as the critical points of the process.

    Materials and Methods

    In this study, the steam generation unit of a juice production company located in Urmia, West Azarbaijan province in Iran was exergetically analyzed. Using mass, energy, and exergy balances for each component of the unit, the thermodynamic objective functions including the exergy efficiency, exergy destruction rate, exergy loss rate, and the potential improvement rate were assessed. After data acquisition, energy and exergy analysis of this unit was achieved by solving the related equations with the help of thermodynamic properties along with programming in EES software package.

    Results and Discussion

    The results showed that the highest exergy efficiency of 98.44% was assigned to the steam distributor (O) of the unit with a potential improvement rate of 1.51 kW and an exergy loss rate of 68.80 kW, as well as the pump (M) before the fourth boiler with an exergy efficiency of 19.69%, had the lowest value of exergy efficiency. The values of 12.55 and 11.93 kW were obtained for the exergy destruction rate and its potential improvement rate, respectively. The highest exergy destruction rate of the unit was for the first boiler with a value of 12391.80 kW, with an efficiency of 19.55% and a potential improvement rate of 10295.26 kW.

    Conclusion

    With regard to the energy and exergy analyses of the steam production system, more than 98% of the exergy destruction rate of the entire steam generation system was assigned to boilers, which had a major contribution to the exergetic efficiency of the system. The highest percentage of potential improvement was related to the first boiler and also the third boiler had the highest exergy loss rate, although the lowest exergy loss rate was the expansion tank of the system. In general, this study demonstrated the importance of exergy analysis for detecting the system components with the highest exergy destruction, which can be a breakthrough to identify these components and provides suitable solutions to improve the overall exergy efficiency of the steam-generating system.

    Keywords: Exergetic efficiency, Exergy destruction rate, Exergy potential improvement rate, Steam generation system
  • H .Farzanpour, S. S .Seiiedlou *, H .Nalbandi Pages 131-146
    Introduction

    In livestock and specifically poultry houses, controlling the internal environment conditions is a key factor to increase animal productivity and prevent their casualties. Controlling the atmospheric conditions like the air temperature and gas concentration in semi-enclosed spaces like poultry houses can improve the living conditions. Experimental tests on the atmospheric conditions of livestock and poultry houses are challengeable and due to limitation of measurement points, unstable climate conditions and experimental errors. Simulation of the air temperature and momentum conditions is used unlimitedly with computer resources by Computational Fluid Dynamics (CFD) methods to overcome the limitations of experimental tests. This method has vast abilities of parametric analysis and predicting the optimum range of functional parameters. So in this research, the air temperature and velocity distribution of a poultry house were simulated using CFD to achieve the best condition for the air ventilation and uniform temperature distribution.   

    Materials and Methods

    In the present study, the geometrical model of poultry house was created using Gambit software and meshed. The mesh independence study was also performed. According to the results, 166550 elements were enough to solve the problem with an acceptable accuracy.The Reynolds-averaged Navier-Stokes (RANS) equation was selected to simulate the momentum transfer inside the poultry house. The k-ε model is one of the most used turbulence models for industrial applications. The main assumption in this model is that the flow is incompressible and that the fluid is Newtonian. A transient heat transfer equation within the fluid domain was selected to predict the air temperature that describes a time-dependent process that includes the conduction and convection terms. All the boundary condition was measured experimentally during 24 hours and their temperature was modeled using the proper mathematical models and applied to the developed model. The mathematical models were solved simultaneously in ANSYS- FLUENT software. The developed simulator was validated experimentally by measuring the air temperature of some specified locations (13 points).

    Results and Discussion

    The results demonstrate that the model enjoyed satisfactory accuracy so that the RMSE value between the measured and predicted air temperature was in the range of 0.405 to 1.29 and the simulator could predict the air temperature with the accuracy of 0.6 degrees. Therefore, it is possible to use the validated simulator for the real-time controlling of poultry houses to optimize the ventilation process. According to the results, the high heterogeneity in the air temperature and about an 18-degree difference was observed in the air temperature distribution at various locations of poultry houses. In addition, the air velocity was not uniform at the different plans of poultry house; especially in the central points of poultry house, it was higher than 1 m/s that is higher than the recommended value. Therefore, the simulator was used to improve the ventilation of the poultry house. The results of various simulations carried out indicated that the angle of the air inlets vents affects the air turbulence. Also, the air temperature and velocity distribution were more uniform when the air inlet vents were across each other. Therefore, some new gates were opened and the angle of the existing gates was changed to improve the ventilation condition of the poultry house. By such modification, the ventilation condition of the poultry house was improved and the air velocity and temperature distribution in the optimized house were more uniform than that observed in the primary one. The air temperature and velocity were in the range of 291 to 297 K (18 to 24 °C) and 0.23 and 0.46 m s-1, respectively. These values are at the recommended condition for poultry houses.

    Conclusion

    The opening angle of the vents had a significant effect on the air distribution. Application of across vents in the  side-walls of poultry house led to uniform distribution of air velocity and temperature. The developed simulator has good performance and accuracy to design and construct poultry houses.

    Keywords: computational fluid dynamics, Numerical simulation, Poultry House, Ventilation
  • A .Mirzaee, M. Soleimani *, H. Bahrami, M .Norouzi Masir Pages 147-157
    Introduction

    Almost 18 percent of emitted greenhouse gasses in Iran come from livestock industries, especially from manure decomposition. With the anaerobic digestion of animal wastes, in addition to eliminating its disadvantages, biogas as a clean and renewable energy carrier is produced. In addition, the resulting sludge is a more healthy and nutritious fertilizer for use in agriculture. One of the challenges of the bio-gas industry is to increase gas production efficiency. Various approaches are proposed to enhance manure digestion efficiency and increase biogas production, which can be mentioned below: Changing operating parameters such as temperature, hydraulic retention time (HRT), and particle size of the substrate; adding some effective additives; returning the resulting sludge into the digestion process and using bio-filters. Therefore in this study, in order to increase biogas production from poultry manure, two methods (co-digestion with rumen contents, and chicken intestine and its contents, and returning the slurry into the reactor) were tested. The alkaline composition of chicken manure and its high content of ammonia makes it difficult to digest alone, and co-digestion with high-carbon organic matter improves its digestibility.

    Materials and Methods

    Polyethylene bottles were used as batch reactor units. In order to the possibility of gas exit, as well as taking samples of the digester, two valves were placed on the bottle cap. All digesters were placed in a hot water bath and a 700 watts electric heater and a thermostat were used respectively to supply heat and to keep the temperature constant. A U-shaped tube, connected to the reactor output pipe was used to measure the amount of produced gas. The volume of water removed from the tube was an indicator of produced gas. The experiment was carried out in two stages. In the first stage 21 reactors were used according to the design of the experiment which was a completely randomized design with 7 treatments (adding rumen fluid in three levels (10, 20, and 30 percent of chicken manure (weight basis), respectively), adding chicken intestines and its content in three levels (10, 20, and 30 percent of chicken manure (weight basis), respectively), and control treatment), and three replicates of each treatment. During the whole experiment period, the pH and temperature were kept constant, respectively between 7.2-8.2 and 40-35 °C (mesophilic range). In the second stage of the experiment, after all the treatments reached the end of their hydraulic retention time, the resulting sludge was filtered and the liquid part was returned to the cycle. Three treatments were also provided here (supplying 50% of the water required by sludge liquid, supplying 100% of the water required by sludge liquid, and control treatment (no liquefied sludge).

    Results and Discussion

    Based on the results, although the type of organic supplementation had a significant effect on the amount of biogas production, the quantity of them had not. Treatments of chicken manure + 20%, 30%, and 10% of chicken intestines resulted in the highest amount of biogas production, respectively. But these three treatments were not significantly different. Also, the co-digestion of chicken manure with chicken intestines was more effective than the co-digestion of chicken manure with rumen fluid. The return of sludge, resulted from anaerobic digestion of chicken manure, again into the cycle, in addition to enhancing the amount of produced gas, can reduce the waiting time to start gas production by at least six days (in the treatment of providing 100% of required water from returned sludge). This can lead to continuous gas production and availability of sufficient gas in commercial gas-producing units. The effect of treatments on the time of reaching the cumulative gas production index to 100 mm was significant (α= 5%) and treatment of S100 reduced this duration by approximately 17 days (65%) and S50, for approximately 16 days (74%). 

    Conclusion

    According to the results of this study, co-digestion of chicken manure with cow rumen fluid did not have a significant effect on the increase of biogas production, but co-digestion of chicken manure with chicken intestine and its contents (at least by 20% of chicken manure (weight basis)) can have a significant effect on the increase in the production of biogas and can increase the amount of gas at least twice. The highest amount of gas volume was about 305 Ml.gr-1  VSadded and came from the treatment of co-digestion of chicken manure with 20% (weight base) chicken intestine and its contents. The return of the resulting sludge of anaerobic digestion of chicken manure, back into the cycle, in addition to increasing the amount of gas, can minimize the time it takes to start to produce gas and help to produce gas continuously. Moreover, the water used for digestion will also be significantly reduced (at least 50%).

    Keywords: Anaerobic digestion, Batch Reactor, Co-digestion, Renewable Energy
  • A. Moghimi, A. Sazgarnia, M. H .Aghkhani * Pages 159-167
    Introduction

    Pistachio production has been adversely affected by Psylla, which is a devastating insect. The primary goal of this study was to select sensitive spectral bands to distinguish pistachio leaves infected by Psylla from healthy leaves. Diagnosis of psylla disease before the onset of visual cues is crucial for making decisions about topical garden management. Since it is not possible to diagnose psylla disease even after the onset of symptoms with the help of color images by drones, hyperspectral and multispectral sensors are needed. The main purpose of this study was to extract spectral bands suitable for distinguishing healthy leaves from psylla leaves. For this purpose, in this paper, a new method for selecting sensitive spectral properties from hyperspectral data with the high spectral resolution is presented. The intelligent selection of sensitive bands is a convenient way to build multispectral sensors for a specific application (in this article, the diagnosis of psylla leaves). Knowledge of disease-sensitive wavelengths can also help researchers analyze multispectral and hyperspectral aerial images captured by satellites or drones.

    Materials and Methods

    A total number of 160 healthy and diseased leaves were scanned in 64 spectral bands between 400-1100 nm with 10 nm spectral resolution. A random forest algorithm was used to identify the importance of features in classifying the dataset into diseased and healthy leaves. After computing the importance of the features, a clustering algorithm was developed to cluster the most important features into six clusters such that the center of clusters was 50 nm apart. To transfer the hyperspectral dataset into a multispectral dataset, the reflectance was averaged in spectral bands within ±15 nm of each cluster center and achieved six broad multispectral bands. Afterwards a support vector machine algorithm was utilized to classify the diseased and healthy leaves using both hyperspectral and multispectral datasets.

    Results and Discussion

    The center of clusters were 468 nm, 598 nm, 710 nm, 791 nm, 858 nm, and 1023 nm, which were calculated by taking the average of all the members assigned to the individual clusters. These are the most informative spectral bands to distinguish the pistachio leaves infected by Psylla from the healthy leaves. The F1-score was 90.91 when the hyperspectral dataset (all bands) was used, while the F1-score was 88.69 for the multispectral dataset. The subtle difference between the F1-scores indicates that the proposed pipeline in this study was able to select appropriately the sensitive bands while retaining all relevant information.

    Conclusion

    The importance of spectral bands in the visible and near-infrared region (between 400 and 1100 nm) was obtained to identify pistachio tree leaves infected with psylla disease. Based on the importance of spectral properties and using a clustering algorithm, six wavelengths were obtained as the best wavelengths for classifying healthy and diseased pistachio leaves. Then, by averaging the wavelengths at a distance of 15 nm from these six centers, the hyperspectral data (64 bands) became multispectral (6 bands). Since the correlation between the wavelengths in the near-infrared region was very high (more than 95%), out of the three selected wavelengths in the near-infrared region (710, 791, and 1023), only the 710-nm wavelength, which was closer to the visible region, was selected. The results of classification of infected and diseased leaves using hyperspectral and multispectral data showed that the degree of classification accuracy decreases by about 2% and if only 4 bands are used, the degree of accuracy decreases by about 3%.The results of this study revealed that the proposed framework could be used for selecting the most informative spectral bands and accordingly develop custom-designed multispectral sensors for disease detection in pistachio. In addition, we could reduce the dimensionality of the hyperspectral datasets and avoid the issues related to the curse of dimensionalitylity.

    Keywords: Classification, Feature selection, hyperspectral data, multispectral data, Pistachio, Psylla, random forest, Spectroscopy
  • E .Chavoshgoli *, Sh .Abdollahpour, H. R. Ghasemzadeh Pages 169-179
    Introduction

    The nut sunflower is usually cultivated in small farms and is harvested with a low capacity of harvester at high moisture content. For the rigid threshing components, impact and knead force are so large as it leads to crushing of the grain or inner stress. This reduces marketability and the germination rate of seeds. The mechanical damage degree of sunflower grain is influenced by the material of the threshing beaters, the velocity of impact, moisture contents, etc. Traditional manual methods, that separate grain from the sunflower head, take a lot of time, require large manpower, have high grain damage, and low efficiency. The objective of the present work was to develop and optimize a threshing unit for nutty sunflower that would combine safe impact velocities with appropriate adjusting of its variable to maximize threshing efficiency whilst minimizing grain damage resulting from shearing, cracking, or crushing.

    Materials and Methods

    The nutty Sunflower heads were procured from the Experimental Orchard of University of Tabriz, Iran at the moisture content of harvesting. Axial threshing units using kinematic equation and properties of the grain, designed and constructed that the variables of its components are adjustable. The beater of the thresher is flexible, which the deformation and vibration undergoing the overall rotation and impact process becomes larger with increasing speed and prevents grain damage. The power required for threshing and separation grain from heads was calculated at about 4.5 kW. Diameter and rotational drum speed value estimated using relation (V=  and study of other researches as considering critical impact velocity of sunflower grain. The length of the thresher was 1.2 m that estimated by determining the capacity and the number of beaters. Threshing efficiency (%), separation efficiency (%), and grain damage (%) were parameters of performance for study. The experimental design by the Response Surface Methodology in Design Expert software 11 with central composite experiment design developed and the affecting parameters on accuracy analyzed and optimized. The threshing unit was evaluated against three threshing drum speeds of 380, 280, and 180 (rpm), feed rates 4000, 3000, and 2000 (kg (head)h-1), moisture content of 60%, 45%, and 30 (%w.b).

    Results and Discussion

    The results showed that the models and effect of variables were statistically significant at the 95% confidence level. The moisture content on threshing efficiency and grain damage had the greatest effect followed by drum speed and feed rate. While for separation efficiency, the feed rate had the most influence. With reducing feed rate and moisture content the threshing efficiency increased, although the decrease in drum speed reduced it. This might be due to sunflower grains adhering loosely to the head at the low moisture contents. The maximum (99.81) and minimum (96.12) percentage of threshed heads was at the moisture content of 30 and 60, respectively. The separation efficiency increased with reducing of feed rate and moisture content. Though, drum speed had insignificant efficacy statistically. The sunflower heads with high moisture content are fragile and brittle, also at high feed rates, the number of impact forces and collisions of heads rises in the condition of threshing. Therefore, the extra MOG is produced and passed from the separator grille. The feed rate of 2000 kg h-1 and moisture content of 30% was the maximum point of separation efficiency that obtained 69.82%. The grain damage decreased significantly with reducing drum speed (380 to 180) and moisture content (60 to 30). This result may be due to the reasons that at higher moisture content the husk of grains becomes soft. The goal of optimization is maximizing threshing and separation efficiency and minimizing grain damage that the optimized values of variables were determined 292.134 rpm for drum speed, 2000 kg h-1 for feed rate, and 30.7406% (w.b) for moisture content.

    Conclusion

    A threshing unit of sunflower, using properties of grains and kinematic equation, was designed and constructed. The models and effect of the variable were statistically significant on performances. The moisture content had a greater effect than other factors on threshing efficiency (%) and grain damage (%). Also, the feed rate of crops in thresher had the most influence on separation efficiency (%). With decreasing the moisture content, threshing and separation efficiency increased and grain damage reduced. The threshing efficiency (%), separation efficiency (%), and grain damage (%) were reported in the range of 96.12 to 99.81, 57.34 to 68.55, and 0.49 to 1.25, respectively. The optimized points were determined at the drum speed of 292.134 m s-1, feed rate of 2000 kg h-1, and moisture content of 30.7406% (w.b).

    Keywords: critical velocity, Nutty sunflower, Optimization, Performance, RSM, threshing
  • M. Hasannia Samakoush, S. R. Mousavi Seyedi *, A .Mahdavian Pages 181-192

    Introdution
    Nowadays, supplying the needed food for people is one of the main global issues. Among foods, rice as the second vital crop has an important role in the world. The amount of global rice losses is about 21 percent and in Iran is reported between 16 to 30 percent that the most amount of it belongs to harvest (mowers and crushers) part. The measuring device for rice picker combine losses at lab scale is a tool which could report the losses of separating and cleaning units. One of the advantages of this device is choosing maximum speed by the operator with considering the acceptable amount of seed losses. Therefore, research about detecting and decreasing this type of losses is important. In this research, only the losses of the harvesting step, especially at the end of a combine harvester machine was addressed. Different methods included piezoelectric and acoustic sensors, load cell, and FIS controller were used as the measuring device of rice picker combine seed losses. In this research, on the contrary with other studies, the slope of meshed plate and humidity of product was measured using a piezoelectric sensor at lab scale under different conditions of the rotational speed of meshed plate. Therefore, the general purpose of this research was design, construction, and evaluation of the measuring device for rice picker combine losses based on the piezoelectric sensor at lab scale to measure the seed losses in the straws at the end of the machine at rice picking.

    Materials and Methods

    A meshed plate with the 100 × 60 cm2 dimension was one of the main parts of the measuring device of seed losses. The diameter of its meshes was 7 mm based on the rice seed size. It separates the rice seeds from straws. Separated seeds from this part were fallen on the other plate which is mounted under the meshed plate. The seeds through four separated routes were fallen on the sensors and output pulses from sensors were sent to the operator plus shown at a monitor. The used seeds at tests were selected from Fajr rice cultivar with a high yield and short height. The used piezoelectric sensor had the ability to convert imposed force and pressure to voltage and vice versa. After the seed falling on the sensor and its vibration, the piezoelectric sensor worked as a beam fixed at one end. The used  Integrated Circuit (IC) was ATMEGA328, which receives the needed data through the sensor as a processing and action system. An electric motor was used to create the rotational speed of meshed plate. The LCD indicator was used for monitoring the obtained data from the test. The amount of seed losses at the end of rice picker combine machine was studied using the piezoelectric sensor with high sensitivity for detecting seeds to separate the seeds from straws. The tested sample in this research was 1 kg straw plus 52 g seed which was equal to 3 percent loss at the end of the harvest combine machine. The experimental design was a simple randomized complete design with three replications. The used treatments included the rotational speed of meshed plate at 3 levels (50, 75, and 100 rpm), the slope of meshed plate at 3 levels (25, 37, and 45 deg) plus humidity at 3 levels (12, 18, and 24 percent). Then the data analysis was done using the conducted test design. The GenStat software was used for data analysis.

    Results and Discussion

    The analysis of variance table showed that all treatments have a significant difference in the number of rice lost seeds at 1% probability level. The interaction between the rotational speed of meshed plate and seed humidity had a significant difference at the 1% level. On this base, the best separation of seed from straw recorded at 100 rpm and 12% humidity. The reason was the higher vibration of the meshed plate at high rotational speed and better separation of seeds at low humidity. Increasing the slope of meshed plate and humidity of seeds caused decreasing in the device efficiency. Because the motion speed of the sample on the meshed plate increased with increasing the slope of the meshed plate, a lower period was needed for separating the seeds from straws, and this separation at higher humidity was done hardly. The highest efficiency at this condition was obtained with 12% humidity and 25º slope. Increment of the rotational speed of meshed plate and decrement of meshed plate slope caused the best separation by the device. Its reason was high vibration at the high rotational speed and having enough time for separating the seeds from straws at a low slope of the meshed plate. The best angle for separating was 37º. Increment of the rotational speed of meshed plate, decrement of meshed plate slope, and sample humidity caused increasing the device efficiency. The reasons were high vibration at high rotational speed, having enough time for separating seeds from straws, and decreasing the compression at low humidity amounts. The results showed that the best device efficiency with 95.51% was obtained at 100 rpm rotational speed, humidity of 12%, and 25º slope of the meshed plate.

    Conclusion

    In this research, a measuring device for detecting the amount of seed losses combined by straws at the end of a rice picker combine machine was designed and constructed, and then was assessed. The results of lab tests showed that increment of the rotational speed of meshed plate plus decrement of meshed plate slope and sample humidity causes an increment of device efficiency. With installation and evaluation of this device on the rice picker combine machine, the needed correction at the farm will be done and the amount of losses will be decreased.

    Keywords: Design, Meshed plate, Piezoelectric, Rice Combine Loss, Sensor
  • E .Alboativi, A .Asakereh *, H. Zaki Dizaji, Y. Mansoori Pages 193-206
    Introduction

    Bagasse is the dry pulpy fibrous residue that remains after sugarcane stalks are crushed for juice extraction. Bagasse is widely used in conversional and by-product industries. Bagasse is commonly used as a substitute for wood in many tropical and subtropical countries for the production of pulp, paper, and board. One of the most important conversional industries in the sugarcane agro-industry is chipboard production. In recent years, two chipboard factories from bagasse were exploited in Khuzestan province. In the production of chipboard from bagasse, a lot of waste is produced, most of which include pith. The waste is transferred to the outside of the factory at a great cost and energy level. Also, annually, a large amount of surplus bagasse of conversional Industries is obtained in Khuzestan agro-industries. These wastes cause many environmental and health problems, while these wastes can be used to generate energy. On the other hand, chipboard industries consume a lot of energy which is mostly fossil energy. Nowadays, in many sugarcane agro-industries in different countries, wastes are used to generate energy for sugar plants and conversional industries. Bagasse is often used as a primary fuel source for sugar mills.

    Materials and Methods

    Current research is focused on the direct energy consumed in chipboard production from sugarcane bagasse and whether it can be provided by using residues and wastes of Debal Khozaie Agro-Industry Company. Data were collected from agro-industry companies as well as by sampling and measuring waste, input and energy consumption at the chipboard factory of Debal Khozaie. Direct energy consumed in the chipboard production from bagasse includes diesel fuel, electricity, natural gas, and labor. Input and output values of materials (bagasse, pith, etc.), and energy consumption (electricity, diesel, natural gas, etc.) were collected using both laboratory tests and data available in agro-industry. Potential of energy generation from bagasse, pith, wood chips, and straw in Debal Khozaie agro-industry, were considered by the direct burning method. Also, the potential of biogas production from vinasse in agro-industry for energy production was calculated. The moisture of bagasse (fresh bagasse, 24 hours, five days, 30 days, and 45 days after gathering), outdoor dried pith, outdoor dried straw and wood chip were measured based on the ASTM D2974 standard method in the laboratory. Ash percentage of bagasse, peat, straw, and Wood chips were measured using a furnace, desiccator and a scale. Also, the lower heating value of bagasse, straw, pith, and wood chips were measured using a calorimeter bomb.

    Results and Discussion

    The direct energy consumption in the chipboard factory was determined to be 5.829 GJ m-3 of produced chipboard. Natural gas and electricity were the major sources of direct energy with 78.52% and 18.87% share, respectively. To replace these sources, pith and woodchips form chipboard factory, sugarcane leaves, remainder sugarcane bagasse, and vinasse from molasses-based Razi alcohol factory were considered. Properties of the substituted resources were determined including ash, moisture content, heating value (using bomb calorimeter), and amount of woodchips along with the biogas potential from anaerobic fermentation of vinasse. Results showed that woody residues from chipboard factory and Debal Khozaie Agro-Industry Company had the potential to provide 4.33 fold the energy provided by gas in the chipboard factory, considering the efficiency equal to 60%. Using the residues of the chipboard factory individually, it is possible to replace all the consumed natural gas and electricity energy needed in the chipboard factory as well. According to the volume of available vinasse, the potential biogas production from this resource estimated to be 8.82 Gm3.

    Conclusion

    Electricity, natural gas, and diesel fuel constitute the direct energy consumed in the production of chipboard, and natural gas with 78.52% has the highest share. Electricity accounts for 18.87% of direct energy consumption. The specific energy of chipboard production at the chipboard factory was 5.829 GJ m-3. Only using the pith of chipboard factory can produce 2.85 times the total energy of natural gas consumed in chipboard factory. Investigation of the potential of biogas production from vinasse in Debal Khozaie agro-industry showed that it is possible to generate energy equivalent to 8824.3 thousand cubic meters of natural gas. Overall, the study showed that using the wastes of chipboard factory and sugarcane agro-industry has the potential to replace the entire natural gas and electricity consumption in chipboard factory.

    Keywords: Bagasse, Heating value, Pith, Sugarcane, Vinasse
  • N. Sedaghat Herfeh, A. M. Nikbakht *, H .Mobli, A.R .Keyhani, A. Piri Pages 207-218
    Introduction

    Sour cherry concentration is a significant agro-industry in the world. In 2016, world production was 13.8 million tons and most of which were processed in the form of concentrate or frozen products. Iran has the 6th rank among the producers of sour cherry and experienced a highly rise (45%) in production in 2016. A conventional energy system evaluation is performed using the energy analysis method. The thermodynamic inefficiencies occurring within the system (factors that cause a gap between performance and ideal state) are not identified and evaluated by energy analysis.

    Materials and Methods

    Pakdis concentrate production line includes a plate heat exchanger (HE) converter to preheat input juice using condensate water energy and crude juice heat outlet, four multipurpose falling evaporators (E1, E2, E3, E4), a distillation tower for raw juice aromatization (DT) and a juice cooling system (JC).A thermographic camera (G120EXD, NEC Avio, Japan) was used for thermographic recording. Initial examination of the thermography results showed that the external surface temperature of the equipment except for the evaporators (E1, E2, E3, E4), the boilers (B1, B2, B3) and the condensation tank of the evaporation line (CT1) had very little difference with the ambient temperature around them, and therefore, their heat flux was ignored.Due to limitations, the mass flow rates of the evaporation line (except for inlet juice) were not measurable, and therefore, energy analysis was used to calculate them. Energy analysis involves the simultaneous resolution of mass and energy balances for a system.

    Results and Discussion

    The heat loss rate from the first evaporator (E1) was calculated to be 21.23 kW from which mass/energy balances and mass flows were extracted. Also, heat loss rate from utilities E2, E3, E4, and CT1 were calculated from mass-energy balances. Streams 32, 49, 52, and 54 are not utilized and exit the system. Hence, they are assigned as heat loss streams within the evaporation line.The total energy loss rate in the evaporation line was calculated to be 4920.82 kW which contributes 74.8% of total input energy to the line. However, 73.39% of this loss is assigned to the cooling tower (stream 54). Stream 29 from the 4th stage evaporator enters the condenser, mixes with water, and provides cold water goes to the cooling tower. In the tower, water evaporates and dissipates heat to the environment. Stream 32 is the second loss stream with 14.8%. Also, it should be noted that heat loss from the surface of utilities makes 3.06% of energy loss of the evaporation line which implies that insulations are done properly in utilities.Evaporation performance may be rated simply and primarily by the steam economy. The value was calculated to be 2.63 in the evaporation line, i.e. 2.63 kg water is evaporated per 1 kg steam injected into the system Exergy rate in several streams of evaporation line. The exergy rate of fuel and products, exergy efficiency, exergy destruction rate, and exergy destruction ratio for each element of the line were reported. Total input exergy to the evaporation line is 4832.03 kW from which 1045.85 kW is destructed due to irreversibility and 3786.19 kW is dissipated.Major destruction occurs within barometric condenser (BC), pressure reducing valve (PR), a plate heat exchanger (HE), evaporators 1 and 2 (E1 and E2), cooling tower (CT), and then evaporators 3 and 4 (E3 and E4). The remaining destruction in other utilities is negligible.

    Conclusion

    Using the first and second laws of thermodynamics and instrumentation procedure, sub-systems of the evaporation unit of Pakdis Company were investigated and energy and exergy balances were coupled and solved. Thermographic assessment of likely zones to energy losses was employed. The whole process was monitored and mass-energy balances were developed. The steam economy as a reliable criterion for evaporation was calculated. To extract inefficiencies and possible optimizable unit operations exergetic analyses were carried out and subsequently the share of exergy loss and destruction and capital cost in the whole process was defined. It was found that capital cost is consistently ignorable compared to exergetic faults such as losses and destructions.

    Keywords: Cherry, Concentrate, Energy Loss, Exergy destruction
  • A. Heidari *, A. Ghadami Firouzabadi Pages 219-229
    Introduction

    Conventional tillage is widely used in sugar beet growing areas. However, conventional farming uses more labour and machines that has a negative effect on soil and the environment. Due to limited water resources and recent droughts, proper use of modern tillage and irrigation methods can increase water efficiency and prevent soil degradation as a result of sustainable agriculture.

    Materials and Methods

    An experiment was conducted to investigate different methods of tillage and water requirements on quantitative and qualitative yield and sugar beet water productivity in the drip irrigation system in Ekbatan Research Station of Hamedan Province from 2018 to 2019. A strip plot experiment with sixteen treatments and three replications was used. Tillage methods in four levels, consisting of T1- plowing with moldboard plow to a depth of 25-30 cm in autumn + power harrow to a depth of 15-20 cm in spring, T2- subsoiling to a depth of 35-40 cm + plowing with moldboard plow to a depth of 25-30 cm in autumn + power harrow to a depth of 15-20 cm in spring, T3- plowing with chisel plow equipped with roller packer to a depth of 25-30 cm in autumn + power harrow to a depth of 15-20 cm in spring and T4- plowing with sweep plow equipped with roller packer to a depth of 25-30 cm in autumn + power harrow to a depth of 15-20 cm in spring and Irrigation factor consisting of I1-100%, I2- 90%,  I3- 80% and I4- 70% sugar beet water requirement were considered. Soil penetration resistance (PR), the volume of water consumption, root yield, sugar yield, white sugar yield and molasses were measured. Water efficiency in tillage and irrigation treatments was also calculated. MSTAT-C software was used for statistical analysis of data. The Duncan's multiple range test at a 1% probability level was used to compare the means.

    Result and Discussion

    At a depth of 0-30 cm, no significant difference was observed between tillage methods on soil penetration resistance. At greater depths (35-40 cm) T2 treatment (subsoil + moldboard plow) had the greatest effect in reducing soil resistance. The results showed that the effect of different tillage methods, water requirement and their interactions at the 1% probability level on root yield; sugar yield and white sugar yield were significant. There was no significant difference between sugar beet yield in the T4 tillage treatment and the conventional method (T1). Treatments T4 (with an average yield of 50686 kg ha-1) and T1 (with an average yield of 50507 kg ha-1) had the highest sugar beet root yield. Also, the tillage method (T4) compared to the conventional tillage method (T1) reduced fuel consumption by 14.7% and increased field capacity by 52.4% respectively. In the T4 tillage method, irrigation treatments I100, I90 and I80 with mean water productivity of 6.113, 6.087 and 5.523 kg m-3 of water consumption, respectively, had the greatest effect on increasing water productivity, while no significant difference was observed between them.

    Conclusion

    The tillage method (T4) compared to the conventional tillage method (T1) reduced fuel consumption by 14.7% and increased field capacity by 52.4%, respectively. There was no significant difference between sugar beet yield and water productivity in the T4 tillage treatment and the conventional method (T1). Although full irrigation treatment (100% water requirement) has the highest water efficiency, there is no significant difference between 90 and 80% water requirement treatment. Therefore, in order to save water consumption, 80% water requirement is recommended. The result is that in the T4 tillage method with a supply of 80% water requirement of sugar beet after plant establishment (approximately from the middle of the growing season) about 12% (1207 m-3) in water consumption without significant reduction in water productivity.

    Keywords: Chisel plow, Drip irrigation, Power harrow, Soil penetration resistance, Subsoiler
  • M .Fereydoni, H. Alizaheh * Pages 231-240
    Introduction

    As the world's population grows, more food need to be produced. Plasma technology is one of the methods that can improve plant growth. Cold plasma is effective in increasing growth and germination indices. In this article, the effect of cold plasma based on corona discharge was investigated on germination of Adel, Mansur, and Azad chickpea varieties.

    Materials and Methods

    In the corona discharge method, a relative vacuum should be used. Corona discharge is formed when there are pronounced spatial in-homogeneities in the electric field, in particular, when the electric field exceeds the breakdown threshold in a limited spatial region. This commonly occurs when highly asymmetric electrodes are employed, such as a point and a plane. Thermodynamically corona is a very non-equilibrium process, creating a non-thermal plasma. The avalanche mechanism does not release enough energy to heat the gas in the corona region generally and ionize it, as occurs in an electric arc or spark. Only a small number of gas molecules take part in the electron avalanches and are ionized, having energies close to the ionization energy of 1- 3 ev, the rest of the surrounding gas is close to ambient temperature. Corona discharge is a weakly ionized non-equilibrium plasma based on the avalanche mechanism. If it reaches a close distance with a conductive material or increase the electrical field, it can create longer breakdown streamers and eventually create sparks. The system is designed to convert 220V voltage with a frequency of 50 Hz to 12 kV voltage with a frequency of 9 kHz. Two electrodes with a 2 cm distance are in a vacuum chamber with a negative pressure of 20 pounds per square inch. And the samples are placed between two electrodes. Experiment was performed in form of a.factorial experimental design based on a CRD. In this plan, treatments are randomly placed in experimental units. The type of factorial experiment performed is 3×3×2×2 and multiplied numbers are factor levels. Seed production year factor in two levels, moisture factor in two levels, Seed variety factor in three levels, and exposure duration factor in three levels were examined. Plasma-exposed seeds and non-exposed seeds were grown under the same conditions. The samples were selected completely randomly. The samples were wetted 24 hours before exposure. Then all 18 chickpeas were placed in a dish in order to observe proper repetition. Samples from each dish were exposed to cold plasma under the same conditions between samples for a specified period of time. After exposing the samples to cold plasma, samples of all dishes under the same conditions at 30 °C and 300 lux environmental light were examined for germination evaluation. For this purpose, samples of each dish were placed in a cover of cotton cloth. They got wet every 4 hours. After 48 hours, all samples were examined and the root length of each sample was measured.

    Results and Discussion

    The results showed that seeds exposed to plasma for 60 seconds had a faster germination speed than those without exposure. Also, seeds that were exposed to plasma for 30 seconds had a longer root length than those without exposure. According to the results of statistical analysis, exposure to cold plasma for 30 seconds has increased root length in Adel chickpea variety up to 12.5% and in Mansour variety up to 18%.

    Conclusion

    After statistical analysis, appear that root length under the same conditions, during 30 seconds of exposure to cold plasma, is significant at 5% level from non-exposure and 60 seconds of exposure. Microscopic images of samples were examined on the outer surface and inner tissue of seed cell. Studies have shown that the outer surfaces of seeds exposed to cold plasma are smoother, less prominent and smaller contact angle than those without exposure to plasma. This change can increase the hydrophilicity of seeds. But cold plasma had no effect on cell tissue in terms of size and number.

    Keywords: Cold Plasma, Microscopic Image, Chickpea, Germination
  • A .Rezaei, H .Masoudi *, H. Zaki Dizaji, M. E .Khorasani Pages 241-252
    Introduction

    The cereal combine harvester is one of the agricultural machines that works in difficult conditions and its parts are constantly under various static and dynamic loads. For the optimal design of vehicle parts, types and values of loads applied to them must be determined correctly. The purpose of this study was to design and fabricate an electronic system that could instantly measure and store the amount of vertical load exerted on the rear axle of grain combine harvester in various conditions to be used in the design and optimization of the axle.

    Materials and Methods

    Main components of the designed system included a steel coupling, a disc loadcell (H2F-C2-10t ZEMIC model), an electronic board for amplifying loadcell output voltage, a data logger (AdvanTech DAQ Navi model), a 12-volt battery, and a laptop. A special steel coupling was designed in CATIA software for connecting the loadcell to the axle. The loadcell was placed between the coupling plates and then the coupling was installed on the center point of the rear axle of a JD 955 combine harvester. A standard tensile-compression testing machine (Cantam STM-150) was used to calibrate the loadcell. The relationship between the input load and the loadcell output voltage was linear and had a high coefficient of determination (R2 = 0.9991). In the static test, the vertical load exerted on the axle was recorded by the electronic system while the combine was stopped and the combine engine was in ON/OFF modes. In the dynamic test, the combine was driven in three positions including asphalt road, dirt road, and wheat field at three different forward speeds, and loads on the rear axle were recorded by the electronic system. Finally, the data obtained from the tests were analyzed as a factorial experiment in a completely randomized design with five replications in Excel and SPSS software.

    Results and Discussion

    The average static loads on the combine rear axle in ON and OFF modes were 14.908 and 14.905 kN, respectively. The results of the Student's t-test of paired samples to compare the values of axle vertical loads in two modes of static load measurement showed that there is no significant difference between the axle loads in ON and OFF mode of the engine at 1% probability level. The average vertical loads on the rear axle of the combine were equal to 15.20, 15.27, and 15.28 kN, while driving on asphalt roads at speeds of 10, 15, and 20 km h-1 respectively. These values were equal to 17.57, 17.99, and 18.15 kN, while driving on the dirt road at speeds of 2, 4, and 6 km h-1 respectively, and they were equal to 16.47, 18.01, and 17.78 kN when harvesting wheat in the field at speeds of 3, 4, and 5 km h-1 respectively. The average load applied on the axle in the turning path was more than the load applied in the straight path, which indicates load transfer to the rear axle during turning. The effect of forward speed and path type on the amount of axle load was significant at a 1% probability level, but their interaction was not significant. Therefore, the critical conditions for applying load on the rear axle of combine harvester are occurred while combine turns with high forward speed, and the design of the axle should be based on these conditions. The maximum load on the axle was obtained equal to 50 kN on the dirt road, which was due to the combine movement on a steep uphill at the end of the path.

    Conclusion

    Evaluation of the system in different conditions showed that the performance and accuracy of the system are acceptable and the data of this system can be trusted and used to measure the vertical load on the rear axle of the combine. The current rear axle of the JD955 combine harvester looks relatively safe, but at some very rugged elevations, especially steep uphills, it suffers from a lot of stress that may cause damage. So, optimizing the axle such as increasing the thickness of the triangular piece in the middle of axis and using a stronger alloy for the middle areas of the axle are recommended.

    Keywords: Cereals combine harvester, Coupling, Electronic system, Load cell, Rear axle