this power point presentation contains about grain quality deterioration from insects, pests, microorganisms, rodents and birds, and their control measures and physiological, chemical changes during storage, moisture migration during storage etc., It contains the principal of fumigation and different types of fumigants and their applications
this power point presentation contains about grain quality deterioration from insects, pests, microorganisms, rodents and birds, and their control measures and physiological, chemical changes during storage, moisture migration during storage etc., It contains the principal of fumigation and different types of fumigants and their applications
I am Sambhav Jain From Dayalbagh Educational INstitute, Agra doing Bsc.[Hons.] Agriculture.I have described here about the irrigation systems in greenhouse to be used by us.
Material handling equipments : conveyors and elevators ajaz malla
Material handling is the movement, protection, storage and control of materials and products throughout manufacturing, warehousing, distribution, consumption and disposal. As a process, material handling incorporates a wide range of manual, semi-automated and automated equipment and systems that support logistics and make the supply chain work.
About the storage of horticultural crops using the advanced technology.Various methods of storage includes: cold storage,controlled atmospheric storage, modified atmospheric storage.
The PPT includes importance of grain drying, moisture content determination methods, equilibrium moisture content, different mode of heat transfer, types of different drying methods, different dryers etc. The presentation is best suitable for graduation level students.
Insect orders bearing predators and parasitoids used in pest control and thei...Nikhil Kumar
IDENTIFICATION OF INSECT PARASITOIDS
A parasitoid is an insect living on or in the body of another insect, called the host from which it gets protection and food during its immature stage and the adults are free living.
In a typical case, eggs are laid on or in the body of the host, the larvae feed on the body contents of the host, pupate either inside or on the host body and emerge as adults.
The hosts are not killed immediately. Most of the parasitoids belong to Hymenoptera (90%) and Diptera (10%).
type of parasitism
Superparasitism:-
When more than one adult of the same species attack the host.
Eg:-Trichospilus pupivara -opisina arenosella
Multiparasitism:-
More than one species attack the host
Eg:-Bethylids and braconids - o.arenosella
Hyperparasitism:-
When a parasitiod is attacked by another parasitiod.
Eg:- Aphid - Aphidius -asaphess
Most insect parasitoid are waps and flies
Most of parasitoides belong to -hymenoptera and diptera
1.Hymenoptera
The ovipositor originates and protrudes ventrally from the abdomen and is used to insert eggs into their hosts. There are three super families.
a) Super Family : ICHNEUMONOIDEA
* Possess long and filiform antennae
* Wings are veined
Example - Family : ICHNEUMONIDAE
Family : BRACONIDAE
b) Super Family : CHALCIDOIDEA
* Mostly smallest parasitoids and gregarious
* Antennae geniculate
* Abdomen very short or globular with very slender propodeum
* Wings without veins
example-Family : CHALCIDIDAE
Family : TRICHOGRAMMATIDAE
Family : EULOPHIDAE
c) Super family : BETHYLOIDEA
* Smaller than Icheneumonoidea and larger than Chalcidoidea
example- Family : BETHYLIDAE
* Eg. Parasierola (= Goniozus) nephantidis, a larval parasitoid on O. arenosella
2) Order : DIPTERA
Family : TACHINIDAE
* Eg. Sturmiopsis inferens, a larval parasitoid on sugarcane shoot borer, Chilo infuscatellus
* Large bristle flies
* Eggs may be macrotype or microtype
* Macrotype eggs are laid directly on the host's body usually attached to the neck region by a glutinous secretion
* Eg. Spoggosia bezziana on O. arenosella
* Microtype eggs are laid on the host plant and the host larvae feeding on the plant tissue ingest them
Predators
predators kill and feed on several to many individual prey during their lifetimes.
Many species of amphibians, birds, mammals, and reptiles prey extensively on insects.
Predatory beetles, flies, lacewings, true bugs (Order Hemiptera), and wasps feed on various pest insects or mites.
Most spiders feed entirely on insects.
Predatory mites that feed primarily on pest spider mites include Amblyseius spp., Neoseiulus spp., and the western predatory mite, Galendromus occidentalis
GIS and Remote Sensing in Diagnosis and Management of Problem Soil with audio...KaminiKumari13
GIS and Remote Sensing in Diagnosis and Management of Problem Soil for agriculture, soil science, agronomy, forestry, land management and planning with audio by Dr. Kamini Roy
TRACTOR TYPES ,COST ANALYSIS OF TRACTOR POWER AND Attached implementsRahul Bhaktani
TRACTOR TYPES ,COST ANALYSIS OF TRACTOR POWER AND Attached implements types of tractor wheel crawler power tiller fixed cost variable cost engg 5211 igkv coa raipur rahul bhaktani B.Sc 2nd year 1st semester
This will provide indetail information about Size reduction such as in brief about size reduction, major principles governing to size reduction, Laws for size reduction and Major Size reduction equipment using in food industries,
I am Sambhav Jain From Dayalbagh Educational INstitute, Agra doing Bsc.[Hons.] Agriculture.I have described here about the irrigation systems in greenhouse to be used by us.
Material handling equipments : conveyors and elevators ajaz malla
Material handling is the movement, protection, storage and control of materials and products throughout manufacturing, warehousing, distribution, consumption and disposal. As a process, material handling incorporates a wide range of manual, semi-automated and automated equipment and systems that support logistics and make the supply chain work.
About the storage of horticultural crops using the advanced technology.Various methods of storage includes: cold storage,controlled atmospheric storage, modified atmospheric storage.
The PPT includes importance of grain drying, moisture content determination methods, equilibrium moisture content, different mode of heat transfer, types of different drying methods, different dryers etc. The presentation is best suitable for graduation level students.
Insect orders bearing predators and parasitoids used in pest control and thei...Nikhil Kumar
IDENTIFICATION OF INSECT PARASITOIDS
A parasitoid is an insect living on or in the body of another insect, called the host from which it gets protection and food during its immature stage and the adults are free living.
In a typical case, eggs are laid on or in the body of the host, the larvae feed on the body contents of the host, pupate either inside or on the host body and emerge as adults.
The hosts are not killed immediately. Most of the parasitoids belong to Hymenoptera (90%) and Diptera (10%).
type of parasitism
Superparasitism:-
When more than one adult of the same species attack the host.
Eg:-Trichospilus pupivara -opisina arenosella
Multiparasitism:-
More than one species attack the host
Eg:-Bethylids and braconids - o.arenosella
Hyperparasitism:-
When a parasitiod is attacked by another parasitiod.
Eg:- Aphid - Aphidius -asaphess
Most insect parasitoid are waps and flies
Most of parasitoides belong to -hymenoptera and diptera
1.Hymenoptera
The ovipositor originates and protrudes ventrally from the abdomen and is used to insert eggs into their hosts. There are three super families.
a) Super Family : ICHNEUMONOIDEA
* Possess long and filiform antennae
* Wings are veined
Example - Family : ICHNEUMONIDAE
Family : BRACONIDAE
b) Super Family : CHALCIDOIDEA
* Mostly smallest parasitoids and gregarious
* Antennae geniculate
* Abdomen very short or globular with very slender propodeum
* Wings without veins
example-Family : CHALCIDIDAE
Family : TRICHOGRAMMATIDAE
Family : EULOPHIDAE
c) Super family : BETHYLOIDEA
* Smaller than Icheneumonoidea and larger than Chalcidoidea
example- Family : BETHYLIDAE
* Eg. Parasierola (= Goniozus) nephantidis, a larval parasitoid on O. arenosella
2) Order : DIPTERA
Family : TACHINIDAE
* Eg. Sturmiopsis inferens, a larval parasitoid on sugarcane shoot borer, Chilo infuscatellus
* Large bristle flies
* Eggs may be macrotype or microtype
* Macrotype eggs are laid directly on the host's body usually attached to the neck region by a glutinous secretion
* Eg. Spoggosia bezziana on O. arenosella
* Microtype eggs are laid on the host plant and the host larvae feeding on the plant tissue ingest them
Predators
predators kill and feed on several to many individual prey during their lifetimes.
Many species of amphibians, birds, mammals, and reptiles prey extensively on insects.
Predatory beetles, flies, lacewings, true bugs (Order Hemiptera), and wasps feed on various pest insects or mites.
Most spiders feed entirely on insects.
Predatory mites that feed primarily on pest spider mites include Amblyseius spp., Neoseiulus spp., and the western predatory mite, Galendromus occidentalis
GIS and Remote Sensing in Diagnosis and Management of Problem Soil with audio...KaminiKumari13
GIS and Remote Sensing in Diagnosis and Management of Problem Soil for agriculture, soil science, agronomy, forestry, land management and planning with audio by Dr. Kamini Roy
TRACTOR TYPES ,COST ANALYSIS OF TRACTOR POWER AND Attached implementsRahul Bhaktani
TRACTOR TYPES ,COST ANALYSIS OF TRACTOR POWER AND Attached implements types of tractor wheel crawler power tiller fixed cost variable cost engg 5211 igkv coa raipur rahul bhaktani B.Sc 2nd year 1st semester
This will provide indetail information about Size reduction such as in brief about size reduction, major principles governing to size reduction, Laws for size reduction and Major Size reduction equipment using in food industries,
The packing arrangement of a powder/granules bed depends on the nature and extent of friction among the particles/granules. The bulk volume of a prills depends on packing arrangement of particles, and the packing
arrangement in turn depends on inter-particular or inter-granular friction or
in other words, bulk volume of a given granules depends on the interparticular friction. Angle of repose, bulk density, particle distribution are other important parameters for this estimation
The packing arrangement of a powder/granules bed depends on the nature and extent of friction among the particles/granules. The bulk volume of a prills depends on packing arrangement of particles, and the packing
arrangement in turn depends on inter-particular or inter-granular friction or in other words, bulk volume of a given granules depends on the interparticular friction. Angle of repose, bulk density, particle distribution are other important parameters for this estimation.
Physics of tablet compression, mechanism of tablet
formation, bonding in tablets, the effect of compressional force on tablet properties, effect
of lubricants on tablet compression, binding, instrumented tablet machines and tooling,
problems associated with large scale manufacturing of tablets.
Selected Physical Properties of Soybean In Relation To Storage DesignIJERA Editor
Bulk density, kernel density, internal friction of Soybean were measured over a moisture content range of 7.4 to
22.22%(wb). First and second order polynomial equations are given which describe the kernel density, bulk
density as well as other properties’ dependence on moisture content. For the grain that was tested, bulk density,
kernel density and specific gravity decreased with moisture content while angle of repose, angle of internal
friction and coefficient of sliding friction increased as moisture content increased. One thousand grain weight
and average diameter increased with moisture content for the crop. Frictional coefficients of the crop was
measured on four structural surface namely: concrete, wood, galvanized sheet metal and mild steel sheet. The
values were maximum for concrete among the four surfaces. The angle of repose was found to be higher than
angle of internal friction in all cases tested. These measurements are necessary in selection of the material and in
determination of pressures and angles of the wall of storage structures.
Temperature Dependence of Density and Dynamic Surface Tension of Groundnut Oi...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Wind Erosion
Effects of Wind Erosion
Factors Affecting Wind Erosion
Mechanics of Wind Erosion
Estimation of Soil Loss Due to Wind Erosion
Wind Erosion Control Measures
Wind Breaks
Shelter Belts
Gully Erosion Control Measures
Temporary check dam
Brushwood dams
One row or single post brush wood dam
Double row post brush wood dams.
Semi permanent dams
Loose rock dam
Netting dam
Log check dam
Permanent check dam
Drop Spillway
Drop inlet spillway
Chute spillway
This presentation includes definition of Soil Erosion, Causes of Soil Erosion, Types of Soil Erosion, Agents of Soil Erosion, Factors Affecting Soil Erosion, Mechanics of Soil Erosion and
Ill Effects of Soil Erosion
Water Erosion Control Measures- Agricultural Lands.pptxAjay Singh Lodhi
This presentation describes about agronomical measures to control water erosion. It includes Crop rotation, crop cover, contour cultivation, strip cropping and mulch tillage practices.
This presentation describes gully erosion, development of gullies, stages of gully development, classification of gullies based of shape, state and size.
This presentation includes description about water erosion, types of water erosion i.e. Raindrop erosion, Sheet erosion, Rill erosion, Gully erosion, Stream bank erosion, Sea-shore erosion Landslide/ slip erosion and Tunnel erosion.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
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The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
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2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Important Engineering properties such as physical, thermal and aero & hydrodynamic properties of cereals, pulses and oilseed
1. IMPORTANT ENGINEERING PROPERTIES
SUCH AS PHYSICAL, THERMAL AND AERO &
HYDRODYNAMIC PROPERTIES OF CEREALS,
PULSES AND OILSEED
Dr. Ajay Singh Lodhi
Assistant Professor
College of Agriculture, Balaghat
Jawahar Lal Krishi Vishwa Vidyalaya, Jabalpur (M.P.)
2. Physical Properties
Shape and size
Shape of the grain is connected with the geometrical form of the grain.
Size of the grain refers to the characteristics of an object which in term
determine how much space it occupies and, within limits, can be
described in terms of length, width, and thickness.
The Shape and size together with other characteristics of the grains is
important in the design of the seed grader. These factors determine the
free flowing or bridging tendencies of the seed mass, and therefore,
determine the suitable handling and feeding equipment.
Sphericity and equivalent diameters are also used to describe the
shape and size, respectively for the grains.
3. Sphericity:- The sphericity (φ) defined as the ratio of the
surface area of sphere having the same volume as that of
the grain to the surface area of the grain.
Sphericity can be calculated from the axial dimensions of
the grain as follows:
Where
𝑑𝑖 = is the diameter of largest inscribed circle
𝑑𝑐 = is the diameter of smallest circumscribed circle
of the particle
The sphericity of different grains varies widely.
𝑆𝑝ℎ𝑒𝑟𝑖𝑐𝑖𝑡𝑦 =
𝑑𝑖
𝑑𝑐
4. Roundness :
It is a measure of the sharpness of the solid material. The
most widely accepted methods for determining the
roundness of irregular particle are given below:
𝑅𝑜𝑢𝑛𝑑𝑛𝑒𝑠𝑠 =
𝐿𝑎𝑟𝑔𝑒𝑠𝑡 𝑝𝑟𝑜𝑗𝑒𝑐𝑡𝑒𝑑 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒 𝑤ℎ𝑒𝑛 𝑖𝑡 𝑖𝑠 𝑖𝑛 𝑛𝑎𝑡𝑢𝑟𝑎𝑙 𝑟𝑒𝑠𝑡 𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛, 𝐴𝑝
𝐴𝑟𝑒𝑎 𝑜𝑓 𝑠𝑚𝑎𝑙𝑙𝑒𝑠𝑡 𝑐𝑖𝑟𝑐𝑢𝑚𝑠𝑐𝑟𝑖𝑏𝑖𝑛𝑔 𝑐𝑖𝑟𝑐𝑙𝑒, 𝐴𝑐
𝑅𝑜𝑢𝑛𝑑𝑛𝑒𝑠𝑠 𝑟𝑎𝑡𝑖𝑜 =
𝑅𝑎𝑑𝑖𝑢𝑠 𝑜𝑓 𝑐𝑢𝑟𝑣𝑎𝑡𝑢𝑟𝑒, 𝑟, 𝑜𝑓 𝑡ℎ𝑒 𝑠ℎ𝑎𝑟𝑝𝑒𝑠𝑡 𝑐𝑜𝑟𝑛𝑒𝑟
𝑀𝑒𝑎𝑛 𝑟𝑎𝑑𝑖𝑢𝑠 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒, 𝑅
5. Bulk Density
The bulk density of a grain can be determined by weighing
a known volume of grain filled uniformly in a measuring
cylinder.
The following equation is used to calculate the bulk density
of the material:
𝜌𝛽 =
𝑊
𝑉
Where
𝜌𝛽 is the bulk density, g/cc or kg/m3
𝑊 is the weight of the material, g or kg
𝑉 is the volume of the material, cc or m3
6. True Density
The mass per unit volume of a material excluding the void
space is termed as its true density.
The simplest technique of measuring true density is by
liquid displacement method, where tube is commonly
used. The expressions used for calculation of true volume
are given as follows:
𝑉𝑜𝑙𝑢𝑚𝑒 𝑐𝑐 =
𝑊𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑑 𝑊𝑎𝑡𝑒𝑟, 𝑔
𝑊𝑒𝑖𝑔ℎ𝑡 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟, 𝑔/𝑐𝑐
𝑉𝑜𝑙𝑢𝑚𝑒 𝑐𝑐 =
(𝑊𝑒𝑖𝑔ℎ𝑡 𝑖𝑛 𝑎𝑖𝑟 − 𝑊𝑒𝑖𝑔ℎ𝑡 𝑖𝑛 𝑊𝑎𝑡𝑒𝑟), 𝑔
𝑊𝑒𝑖𝑔ℎ𝑡 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟, 𝑔/𝑐𝑐
7. Porosity
It is defined as the percentage of volume of inter-grain
space to the total volume of grain bulk. The percent void of
different grains in bulk is often needed in drying, airflow,
and heat flow studies of grains.
Porosity depends on (a) shape, (b) dimensions, and (c)
roughness of the grain surface.
Porosity of some crops is tabulated as follows:
The grain porosity can be measured by using an air
comparison pycnometer or by the mercury displacement
method (Thompson and Issas, 1967).
Grain Porosity (%)
Corn 40 – 45%
Wheat 50 – 55%
Paddy 48 – 50%
Oats 65 – 70%
8. Coefficient of Friction and angle of repose
Angle of repose and frictional properties of grains play an
important role in selection of design features of hoppers,
chutes, dryers, storage bins, and other equipment for grain
flow.
Coefficient of Friction
The coefficient of friction between granular materials is
equal to the tangent of the angle of internal friction for the
material. The frictional coefficient depends on (a) grain
shape, (b) surface characteristics, and (c) moisture content.
9. Angle of Repose
The angle of repose of grain can be determined by the
following method.
Grain is poured slowly and uniformly onto a circular
platform of 6.5 cm diameter to form a cone. The height of
this cone is measured using a traveling microscope.
The angle of repose of grain at different moisture contents
is determined from the geometry of the cone formed (Dutta
et al., 1988).
It is the angle made by the surface of the cone with
horizontal.
“The angle of repose is the angle between the base and
the slope of the cone formed on a free vertical fall of the
granular material to a horizontal plane. The size, shape,
moisture content and orientation of the grains affect the
angle of repose.”
10. Angle of Repose is calculated using the following equation:
𝜑𝐴𝑅 = 𝑡𝑎𝑛−1
2(𝐻𝑎 − 𝐻𝑏)
𝐷𝑏
Where
𝜑𝐴𝑅 is the angle of repose, degrees
𝐻𝑎 is the height of the cone, cm or m
𝐻𝑏 is the height of the Platform, cm or m
𝐷𝑏 is the diameter of the
platform, cm or m
11. THERMAL PROPERTIES
Specific heat : The specific heat may be defined as the amount
of heat in kilo-calories that must be added to or removed from 1
kg of a substance to change its temperature by 1°C.
The specific heat of wet agricultural material is the sum of
specific heats of bone dry material and its moisture content.
If Cd and Cw are the specific heats of bone dry material and
water respectively, and in is the moisture content of the material
in percent wet basis, then the specific heat can be expressed as
given below
𝐶 =
𝑚
100
𝐶𝑤 +
100−𝑚
100
𝐶𝑑
𝑘𝑐𝑎𝑙
𝐾𝑔
℃
m is the moisture content of the grain, percent (wet bulb
temperature)
The specific heat of bone dry grain varies from 0.35 to 0.45 kcal/kg or
1.46 to 1.88 kJ/kg °C.
12. Thermal conductivity :
The thermal conductivity is defined as the amount of heat flow
through unit thickness of material over a unit area per unit time
for unit temperature difference.
The thermal conductivity of the single grain varies from 0.3 to
0.6 kcal/(m·h °C), whereas the thermal conductivity of grains in
bulk is about 0.10 to 0.15 kcal/(m·h °C), which is due to the
presence of air space in it. The thermal conductivity of air is
0.02 kcal/(m·h °C) only.
The thermal conductivity can be expressed by the following
equation
𝑄 = 𝐾𝐴∆𝑇
Where Q = amount of heat flow, k cal
A= area, m2
∆𝑇 = temperature difference in the direction of heat
flow, °C
K= thermal conductivity, k cal/m.hr.°C
13. AERO AND HYDRODYNAMIC PROPERTIES
Terminal Velocity:
The air velocity at which an object remains suspended in a
vertical pipe under the action of the air current is called terminal
velocity of the object.
Thus, in free fall, the object attains a constant terminal velocity,
Vt, when the gravitational accelerating force, Fg, becomes equal
to the resisting upward drag force Fr. Hence, Fg = Fr when V =
Vt.
𝑉𝑡 =
2𝑊(𝜌𝑣 − 𝜌𝑓
𝜌𝑣𝜌𝑓𝑎𝑣𝑐
1/2
Where
Vt is the terminal velocity, m/s
W is the weight of the particle, kg
ρv and ρf are mass densities of the particles and fluids,
(kg s2)/m4
av is the projected area of the particle perpendicular to the
direction of motion, m2
c is the overall drag coefficient (dimensionless)
14. Drag coefficient
When a particle is immersed in a
fluid current the forces acting on the
particle has been illustrated in Fig.
If Fy is the drag force and FH is lift
force, then the resultant force, FR
may be calculated by resolving the
forces.
𝐹𝑟 = 𝐶𝐴𝑝
𝜌𝑓𝑣2
2
Where,
FR = resistance drag force or weight of particle at terminal velocity, kg C =
Overall drag coefficient
𝜌𝑓 = mass density of fluid Kgs2/m4,
Ap = projected area of the particle normal to direction of motion, m2
V = relative velocity between main body of fluid and material, m/s
15. The drag coefficient of the material and its resistance to
air flow depend upon,
The bed thickness of the material,
Type, shape and size of grain,
The air velocity and
Orientation and packing of the material.
16. Rheological properties
The rheological properties may be defined as the science
which deals with the deformation and flow of the material
under action of the applied forces.
Time is an important parameter during application of load to
the body. Therefore, in rheology three important parameters
such as force, deformation and time are used for
expressing the mechanical behaviour of the material.
Strain
The unit change, due to force, in the size or shape of a
body referred to its original size or shape. Strain is a non-
dimensional quantity, but it is frequently expressed
centimeters per centimeter, m/m, mm/mm etc.
17. Stress
It is defined as the intensity of a point in a body of the
internal forces or components of force that act on a given
plane through the point. Stress is expressed in force per
unit of area (Kg/mm2).
Compressive strength
It is the maximum compressive stress which a material is
capable of sustaining. Compressive strength is calculated
from the maximum load during a compression test and the
original cross sectional area of the specimen.
Elastic Limit
The greatest stress which a material is capable of
sustaining without any permanent strain remaining upon
complete release of the stress.
18. Modulus of elasticity
It is the ratio of stress to corresponding strain below the
proportional limit.
Poisson’s ratio
The absolute value of the ratio of transverse strain to the
corresponding axial strain resulting from uniformly
distributed axial stress below the proportional limit of the
material.
Tensile strength
The maximum tensile stress that a material is capable of
sustaining.